GIFT   OF 
Dean  Frank  H.    Probert 


Mining  Dept. 


HANDBOOK  OF  MINING  DETAILS 


McGraw-Hill  BookCompany 


Electrical  World         Ite  Engineering  ardMining  Journal 
Engineering  Record  Engineering  News 

Railway  Age  Gazette  American  Machinist 

Signal  Engineer  AmericauEtigineer 

Electric  Railway  Journal  Coal  Age 

Metallurgical  and  Chem  ical  Engineering  P  owe  r 


HANDBOOK 


OF 


MINING  DETAILS 


COMPILED  FROM  THE 

ENGINEERING  AND  MINING  JOURNAL 


BY 

THE  EDITORIAL  STAFF 


McGRAW-HILL   BOOK  COMPANY 

239  WEST  39TH  STREET,  NEW  YORK 

6  BOUVERIE  STREET,  LONDON,  E.  C. 

1912 


SIFT  Off 

FrfANK  H 

MINING  DEPI. 


COPYRIGHT,  1912,  BY  THE 
MCGRAW-HILL  BOOK  COMPANY 


OT. 


THE. MAPLE. PRESS- YORK. PA 


PREFACE 

This  book  is  a  collection  of  articles  that  have  appeared  in  the  Engineering 
and  Mining  Journal  during  the  last  two  or  three  years  under  the  general  head 
of  "Details  of  Practical  Mining,"  a  department  of  the  Journal  that  has  been 
appreciated  highly  by  its  readers,  many  of  whom  have  expressed  the  wish  that 
a  collection  in  book  form  be  made,  which  has  now  been  done. 

In  the  editing  of  this  volume,  the  work  has  been  chiefly  in  the  selection  of  the 
material  and  its  arrangement  in  chapters.  Now  and  then  it  has  been  possible 
to  excise  some  paragraphs  as  being  unessential  and  occasionally  the  phraseology 
of  some  articles  has  been  altered  a  little,  the  requirements  of  preparation  for 
the  original  weekly  publication  not  always  having  permitted  leisurely  considera- 
tion, but  in  the  main  the  articles  now  presented  in  this  book  are  as  they  were 
given  in  the  pages  of  the  Engineering  and  Mining  Journal.  However,  it  has 
been  necessary  in  a  few  cases  to  reduce  the  size  of  the  engravings. 

In  making  this  collection  the  limitation  of  space  necessitated  the  rejection 
of  all  material  that  did  not  pertain  to  the  subjects  selected  for  the  chapters  of 
the  book,  and  even  so  it  was  necessary  to  dismiss  some  of  the  longer  articles 
pertaining  to  them,  which  approached  the  character,  of  essays  rather  than  being 
the  description  and  discussion  of  details.  Of  course  a  wealth  of  contributions 
pertaining  to  the  arts  of  ore  dressing  and  metallurgy  had  to  be  rejected  sum- 
marily. The  compilation  covers  the  publications  in  the  Engineering  and 
Mining  Journal  from  Aug.  7,  1909,  to  July  i,  1912.  If  all  of  the  material  that 
appeared  in  this  department  of  the  Journal  during  that  period  of  three  years  had 
been  used  it  would  have  been  necessary  to  make  a  book  of  several  times  the 
size  of  this. 

No  claim  is  made  that  this  book  is  a  treatise,  exhausting  its  subject,  or  any 
part  of  it.  It  is  simply  a  handbook  that  is  a  more  or  less  random  collection  of 
useful  information,  being  just  what  passes  through  the  pages  of  the  Engineering 
and  Mining  Journal  in  the  course  of  a  few  years.  No  special  attempt  to  round 
out  any  subject  has  been  made.  Yet  it  will  be  found  that  some  subjects  are 
fully  treated. 

With  regard  to  the  authority  of  what  is  to  be  found  in  these  pages:  The 
matter  in  the  main  is  merely  descriptive  of  what  is  done.  Nevertheless,  there 
is  frequently  the  injection  of  opinion  and  advice.  A  great  technical  journal  is 
directed  by  its  editor  and  is  shaped  by  its  editorial  staff,  but  it  is  essentially  the 
product  of  its  contributors.  It  is  a  co-operative  institution  and  its  pages  are  a 
symposium  of  the  experiences  and  views  of  many  professional  men.  During 
the  18  months  ending  with  June  30,  1912,  there  were  460  contributors  to  the 


VI  PREFACE 

Engineering  and  Mining  Journal,  exclusive  of  the  members  of  the  editorial  staff, 
and  its  regular  coadjutors,  and  its  news  correspondents.  Many  of  these  con- 
tributors furnished  articles  that  are  now  collected  in  this  book.  Their  articles 
generally  are  signed.  The  unsigned  articles  are  chiefly  the  work  of  members 
of  the  editorial  staff  of  the  Journal  who  have  been  sent  into  the  field  to  study 
mining  practice. 

The  heterogeneous  authorship  of  this  book  naturally  gives  rise  to  some  in- 
consistencies, some  differences  of  opinion  and  some  conflicts  in  advice.  It  has 
seemed  to  me  best  to  let  these  stand  just  as  in  the  original,  since  they  are  often 
merely  the  reflection  of  different  conditions  prevailing  in  different  parts  of  the 
country,  and  if  carefully  read,  absence  of  unity  in  this  respect  will  not  be  mis- 
leading. 

W.  R.  INGALLS. 

October  i,  1912 


CONTENTS 

CHAPTER  I 

PAGE 

GENERAL  NOTES I 

Checking  Men  in  and  out  of  Mines — Mining  Records  (by  Frederick  T.  Rubidge) — 
Standard  Cost  Sheets — Labor  Wasting  and  Labor  Saving  (by  S.  A.  Worcester) — 
Labor  and  Tonnage  Charts  as  Aids  in  Reducing  Costs  (by  Claude  T.  Rice) — The 
Automobile  in  Mining — Acetylene  Lamps — Candle  Tests  (by  Claude  T.  Rice) — 
Underground  Repair  Shops — Abandoned  Shafts  and  Open  Cuts — Speaking  Tubes 
in  Mines  (by  Lee  L.  Wilcox) — Improvements  in  Mine  Bunks — Portable  Houses — 
A  Sanitary  Underground  Latrine — Inspection  Department  of  the  Goldfield  Consoli- 
dated— Goldfield  Consolidated  Fire  Equipment  (by  Claude  T.  Rice) — The  Diamond 
Hitch  (by  W.  H.  Storms) — Splicing  Wire  Rope — A  Guy  Rope  Tightener — Disposal 
of  Waste — Mine  Tailings  for  Filling  (by  Lucius  L.  Wittich) — Strength  of  a  Mine 
Dam. 


CHAPTER  II 

EXPLOSIVES 24 

Don'ts  in  Using  Explosives — Preparations  for  Blasting  (by  M.  T.  Hoster) — Table 
for  Cutting  Fuse — Blasting  in  Wet  Shafts  (by  E.  M.  Weston) — Blasting  in  Wet 
Ground — The  Calumet  System  of  Lighting  Fuse — Prevention  of  Drilling  into  Mis- 
fired Holes  (by  John  T.  Fuller) — Cartridges  for  Tamping — Use  of  High  Explosives — 
Joplin  Scraper  and  Loading  Stick — Breaking  Ground  for  Steam  Shovels — The 
Necessity  for  Strong  Detonators — Priming  with  Electric  Fuse — Device  for  Clearing 
a  Hung-up  Chute  (by  J.  Bowie  Wilson) — Powder  Magazines — Powder  House  with 
Concrete  Roof  (by  Claude  T.  Rice) — Concrete  Powder  House — Powder  Storage 
Underground — Thawing  Dynamite — Thawing  Dynamite  by  Electricity. 


CHAPTER  III 

ROCK  DRILLS 46 

Air  Hammer  Drilling  in  Sticky  Ground  (by  George  E.  Addy) — A  Drill  for  Soft 
Ground— Design  of  Drill  Bits  (by  Ward  Blackburn)— Rand  Drill  Steel  and  Bits 
(by  E.  M.  Weston)— Ejecting  Sludge  from  Drill  Holes  (by  E.  M.  Weston)— Improved 
Chuck  for  Piston  Drills — Shaping  Chuck  Bolts  (by  H.  Lawrence  Brown) — Improved 
Drill  Post  Collar  (by  Albert  Mendelsohn) — Drill  Post  with  Removable  Screw — 
Jack  for  Machine  Drill  Columns — Removing  Stuck  Drills — Wrench  for  Removing 
Stuck  Drills  (by  Claude  T.  Rice)— Wrinkle  for  Piston  Drill— Cleaning  Drill  Holes  (by 
J.  H.  Forell) — Preventing  of  Freezing  of  Air  Exhaust — Cutting  Timber  by  Small 
Hammer  Drills — An  Air  Moil  for  Cutting  Timber  Hitches  (by  S.  H.  Hill) — Boring 
Flat  Holes  with  Air  Hammer  Drills  (by  Clarence  C.  Semple)— Drilling  with  Double 
Screw  Columns  (by  P.  B.  McDonald) — Bundling  Drill  Steel — Handling  Drill  Steel 
at  Champion  Mine — Mine  Dust  Prevention  on  the  Rand  (by  E.  M.  Weston) — The 
Dwyer  Dust  Arrester — Water  Blast  for  Allaying  Dust. 

vii 


viii  CONTENTS 

CHAPTER  IV 

PAGE 

SHAFT  WORK     68 

Shaft  Sinking  at  the  Pioneer  Mine — Rapid  Shaft  Sinking  in  Butte  (by  C.  J.  Stone) — 
Shaft  Sinking  at  Stella  Mine,  New  York— Bucket  Trolley  for  Shaft  Sinking  (by 
L.  E.  Ives) — A  Two-way  Shaft — Securing  Loose  Rock  by  Bolts — Necessity  for 
Strong  Partitions  in  Shafts — Corner  Framing  of  Shaft  Timbers  (by  W.  H.  Storms) 
— Method  of  Extending  Shaft  Timbers  (by  D.  A.  McMillen) — Shaft  Timbering  at 
the  Keystone  Mine  (by  William  H.  Storms) — Rogers  Shaft  at  Iron  River,  Michigan 
(by  H.  L.  Botsford) — Combination  Post  and  Set  Timbering  in  Shafts  (by  Claude 
T.  Rice) — Timbering  Swelling  Ground  (by  George  C.  McFarlane) — Placing  Shaft 
Timbers — Supporting  Guides  or  Runners  in  Shaft — Holding  Shaft  Timbers  with 
Wire  Cables— Steel  Shaft  Sets  on  the  Mesabi  Range  (by  F.  A.  Kennedy)— Arrange- 
ment for  Guiding  a  Drop  Shaft — Concrete  in  Inclined  Shafts  (by  Sheldon  Smillie) — 
Injection  of  Grouting  behind  Shaft  Tubbing — Grouting  in  Quicksand — Shaft  Station 
in  Inclined  Foot  Wall  Shaft  (by  Claude  T.  Rice) — Large  Underground  Station  in  a 
Coeur  d'Alene  Mine — Concerte  Floors  for  Shaft  Stations — Skip  Pockets — Skip 
Pocket  and  Station  at  Leonard  Mine,  Butte. 

CHAPTER  V 

DRIVING  ADITS  AND  DRIFTS 101 

Fast  Drifting — Maintaining  Grade  in  Driving — Alignment  in  Driving — Placing 
Holes  for  Blasting  (by  P.  B.  McDonald) — Drifting  with  Stope  Drills  (by  Horace 
Lunt) — Driving  Inclined  Raises  with  Stoping  Drills  (by  Arthur  O.  Christensen) — 
Driving  Vertical  Raises  with  Stoping  Drills  (by  Arthur  O.  Christensen) — Staple  for 
Temporary  Staging — Framing  for  Tunnel  Sets — Comparative  Strength  of  Several 
Styles  of  Framed  Timber  Sets  (by  K.  C.  Parrish)— Reinforced  Concrete  in  a  Tunnel— 
A  Method  of  Mining  in  Heavy  Ground  (by  W.  L.  Fleming) — Driving  in  Loose 
Ground  (by  George  J.  Young) — False  Set  for  Spiling  Ground  (by  James  Humes) — 
Drift  Timbering  for  Heavy  Ground — Finger-pin  Timbering  in  Swelling  Ground — 
Joint  for  Drift  Timbers. 

CHAPTER  VI 

STOPING •.,....">' ".    ...   121 

Stoping  with  the  Slicing  System — Stoping  at  Goldiield  Consolidated — A  Modified 
System  of  Back  Stoping  (by  J.  E.  Wilson) — Eliminating  Shoveling  in  Square  Set 
Stopes — Recovering  Ore  from  Pillars — Scaffolding  for  Drills  in  Wide  Stopes — Placing 
Holes  in  Breast  Stoping  (by  Harvey  S.  Brown) — A  Method  of  Blasting  in  Stopes — 
Obtaining  Cheap  Stope  Filling — "Sand  Filling"  Stopes  in  the  Transvaal — The  Use 
of  Cyanide  Tailings  for  Stope  Fillings — Mining  Dangerous  Ground  on  the  Mesabi 
Range  (by  B.  M.  Concklin) — Method  of  Rigging  Ladders  to  Reach  Stope  Backs — 
Staging  for  High  Set-ups  in  Stopes — Chain  Ladders  in  Waste  Chute — Notes  on 
Placing  and  Cutting  Stulls — Framing  of  Round  Timbers  (by  Percy  E.  Barbou~N — 
Leaning  Stope  Sets— Battery  Method  of  Stull  Timbering  (by  Claude  T.  Rice,  - 
Timbering  Wide  Stopes — Placing  Sills  Beneath  Square  Sets  Already  in  Place — 
Centennial-Eureka  Chute  Pocket  and  Gate — Steel  Ore  Chute  for  Use  in  High- 
grade  Stopes — Bulkheaded  Ore  Chutes — Lining  for  Ore  Chutes — Safeguarding  Ore 
Chutes — Gate  for  Ore  Bin  Chutes  (by  Algernon  Del  Mar) — Ore  Crushing  Plant l 
Underground — Underground  Grizzlies — A  Movable  Picking  Floor — A  Modified 
Chinaman — Ore  Chute  Construction — A  Standard  Ore  Chute  (by  S.  S.  Arentz). 


CONTENTS  ix 

CHAPTER  VII 

PAGE 

HEADFRAMES,  CHUTES,  POCKETS,  ETC I49 

Gate  for  Ore  Chute — Chute  Gate  at  Mammoth  Mine,  Kennett,  Cal. — Gate  for 
Lump  Ore  Bin  (by  Guy  C.  Stoltz)—  A  Finger  Chute  (by  A.  Livingstone  Oke)— 
Steel  Arc  Chute  Gate — Cananea  Arc  Type  Gate — Skip  Loader  at  the  Original 
Consolidated — Measuring  Pocket  for  Skips — Skip  Loading  Chute — Whitford-M  lls 
Skip  Loading  Device  (by  E.  M.  Weston) — Red  Jacket  Ore  Pockets — Measuring 
Pocket  for  an  Inclined  Shaft — An  Underground  Ore  Pocket — How  to  Erect  Three- 
leg  Shears  (by  A.  Livingstone  Oke) — Headframe  for  a  Prospect  Shaft — Headframe 
for  a  Winze  Hoist — An  Underground  Hoist — Details  of  a  Wooden  Headframe — 
Overwinding  Allowance  in  Head  Gears — Tipple  Construction  in  the  Birmingham 
District — Cananea  Ore  Bins  (by  Claude  T.  Rice) — Tonopah  Orehouses — Concrete 
Storage  Bin  (by  Fremont  N.  Turgeon). 

CHAPTER  VIII 

HOISTING  AND  TRANSPORTATION 177 

Graphic  Solutions  of  Skip  Loads  (by  F.  W.  Collins)— Vertical  Unbalanced  Loads 
Lifted  by  First  Motion  Hoist — Determining  the  Rope  Speed  in  Hoisting — Determin- 
ing the  Number  of  Cars  Hoisted  per  Hour — Determining  the  Face  of  Winding 
Drums — Determining  the  Amount  of  Rope  Wound  on  a  Drum — Power  Required 
to  Haul  %Cars  on  Various  Pitches — Rope  Capacity  of  Drums — Flat  Rope  vs.  Round 
Rope — Remarks  on  Hoisting  Ropes — Uses  for  Old  Hoisting  Cable — Gravity  Planes 
at  Cheever  Mine  (by  Guy  C.  Stoltz) — Car  Stopping  Devices  on  Gravity  Inclines — 
Tail  Rope  Haulage  Operated  by  Skips — An  Underground  Haulage  System  (by  Albert 
H.  Fay) — An  Underground  Hoisting  Station  (by  S.  A.  Worcester) — Catenary  Hoisting 
Cable— Double  Hoisting  Cables— Hoisting  Cable  Run  through  a  Drill  Hole— Rapid 
Hoisting  with  Wire  Guide  (by  Hugh  C.  Watson) — Concrete  Chute  Bridging  a 
Level — A  Cheap  Mine  Road  (by  S.  H.  Brockunier) — Snatch  Blocks  Applied  to 
Hoisting  (by  Stephen  L.  Goodale) — A  Simple  Form  of  Lift — Cable  Drum  for 
Lowering  Timber — A  Portable  Winch — Combination  Timber  Hoist  and  Winch — 
Interchangeable  Arrangement  for  Steam  and  Electric  Hoist — A  Cone  Friction  for 
Mine  Hoists — Deep  Sinking  with  Gasoline  Hoists — Steam  Hoists  for  Shallow  Mines 
(by  Sven  T.  Nelson) — Sheave  Supports  for  Underground  Hoists — Arrangement  of 
Sheaves  at  the  Tobin  Mine — Rope  Guard  for  Idler — Rope  Idlers  for  Inclined 
Shaft — Idler  for  Hoisting  Rope  in  Inclines — Device  for  Prevention  of  Overwinding — 
Device  for  Cleaning  Flat  Wire  Cables  (By  M.  J.  McGill)— Mine  Signal  Switch- 
Electric  Signals  for  Underground  Tramways  (by  W.  S.  Grether) — An  Electric  Signal 
Device  (by  P.  B.  McDonald)— Hand  Bell  Signal  Wiring  (by  Guy  C.  Stoltz)— The 
Solution  of  a  Cableway  Hoist  Problem — Turning  Device  for  Tramway  Track 
Cables — Cable  Clamp  for  Tramway  (by  Claude  T.  Rice) — Oiling  Tramway  Track 
Cables — Oiler  for  Tramway  Buckets — Anchoring  Wire  Ropes  (by  A.  Living- 
stone Oke). 

CHAPTER  IX 

SKIPS,  CAGES,  CARS  AND  BUCKETS  .......  222 

Drill-steel  Bucket — Tram  Car  for  the  Prospector  (by  Guy  C.  Stoltz) — The  Mineville 
Cre  Bucket — Joplin  Bucket  Cars — Wooden  Ore  Car — A  Joplin  Car  for  Boulders 
(by  Claude  T.  Rice) — Tram  Car  for  Stope  Filling — Tram  Car  with  Automatic  Door — 
Side  Dump  Mine  Car  (by  Claude  T.  Rice) — Cradle  for  Dumping  Mine  Cars — 


CONTENTS 

PAGE 

Calumet  &  Hecla  Ore  Cars — Coeur  d'Alene  Mine  Car — A  Copper  Range  Man 
Car— Copper  Range  Ore  Skip— The  Franklin  Ore  Skip— The  Franklin  lo-ton 
Skip — Skip  and  Dump  Plate  for  Vertical  Shaft  (by  L.  L.  Wilcox) — Automatic  Skip 
for  Inclined  Shafts — Dumping  Skip  for  Winze  (by  K.  Baumgarten) — A  Timber 
Skip — Counterbalance  for  Skips — Skip  Improvements — A  Three-deck  Man-cage — 
Hiawatha  Mine  Cage  (by  H.  L.  Botsford)— A  Light  Mine  Cage  (by  H.  L.  Botsford) 
— Harness  for  Lowering  Mule  Down  a  Shaft  (by  W.  F.  Boericke) — Automatically 
Discharging  Bailers  (by  W.  H.  Storms) — A  Two-ton  Water  Car  (by  Guy  C.  Stoltz) 
— Scraper  for  Cleaning  Stopes — A  Scheme  for  Transporting  Lumber  (by  W.  F.  Du 
Bois) — A  Wagon  Oil  Tank  (by  Chester  Steinem)— An  Automatic  Bucket  Tripping 
Device — Safety  Dump  for  Sinking  Bucket — Self-dumping  Bucket  for  Winze  (by 
Lawrence  May) — Automatic  Bucket  Dump — Method  of  Handling  Sinking  Buckets 
(by  W.  B.  Baggaley) — Type  of  Skip  Dumps  in  New  York  Iron  Mines  (by  Guy  C. 
Stoltz) — The  Orig'nal  Consolidated  Self-dumping  Skip — Skip  Changing  Device  at 
Leonard  No.  2  Shaft — Crane  for  Changing  Skips — Self-acting  Tipple — Tram  Car 
Tipple  (by  Guy  C.  Stoltz)— Revolving  Tipple— Automatic  Trip  for  Ore  Cars. 


CHAPTER  X 

SAFETY  APPLIANCES  FOR  HOISTING  AND  TRAMMING 273 

Hoisting  Bucket  Hooks — A  Safety  Hook  for  Hoists — Safety  Crane  Hooks — Thimble 
for  Hoisting  Cable — Safety  Crossheads  for  Hoisting  Buckets — Safety  Crosshead  for 
Bucket  Shaft— The  Bryant  Safety  Crosshead— Safety  Catch  for  Cage  (by  H.  L. 
Botsford) — Skip  Chairs  at  Argonaut  Mine — Landing  Chair  for  Skips  in  Inclines — 
Emergency  Chairs  on  Headframe — Testing  Safety  Devices  on  Mine  Cages — 
Cage  Landing  Chairs  (W.  F.  Boericke) — Improved  Landing  Chair — Chairs  on  the 
Cage— Landing  Chair  for  Cage  (by  C.  L.  Se very) —Safety  Gate  for  Cages  (by  R.  B. 
Wallace) — A  Safety  Device  for  Cages  at  the  Chapin  Mine — Shaft  Gates — Anaconda 
Gates  (by  F.  L.  Fisher)— Guards  at  Shaft  Stations— Mine  Track  (by  Alvin  R. 
Kenner) — A  New  Track  Spike — Short  Guard  Rail  Fastening  (by  G.  M.  Shoe- 
maker)—Mining  Track  Frog— Mine  Track  Switches— Calculating  a  Crossover 
Switch— Gravity  Tram  Switch  (by  B.  A.  Statz)— A  Double  Gage  Turnout 
— An  Automatic  Switch — A  Convenient  Switch-throwing  Device — Turntable  for 
Mine  Cars — A  Ball-bearing  Turntable. 


CHAPTER  XI 

PUMPING  AND  DRAINING 307 

A  Useful  Pump  Formula  (by  A.  Livingstone  Oke) — Un watering  Flooded  Mines  (by 
D.  Lament) — The  Sinking  Pump  and  Its  Troubles  (by  M.  T.  Hoster) — Unwatering 
a  Mine  with  Electric  Turbine  Pumps  (by  Percy  E.  B  arbour) — An  Automatic  Cut-off 
for  Electric  Pumps — Pumps  for  Fire  Protection  (A.  W.  Newberry) — Repairing  a 
Cracked  Pump  Cylinder — Air  Escape  on  Small  Pump  Columns — Concrete  Water 
Column — Expansion  Joint  for  Pipe  Lines  (by  C.  L.  Edholm) — Utilizing  Water  in 
Mines — Pump  Station  at  Leonard  Mine,  Butte — Notes  on  the  Pohle  Air  Lift  (by  W.  S. 
Anderson) — Unwatering  Shaft  by  Compressed  Air  (by  Louis  Boudoire) — Mine 
Eductors  (by  Oskar  Nagel) — Draining  a  Shaft  through  a  Drill  Hole  (by  Lucius  L. 
Wittich) — Draining  with  Well  Points — Draining  an  Ore  Chute  (by  Arthur  O. 
Christensen) — Draining  Gravity  Planes — Gate  for  Controlling  Mine  Water — 
Stopping  the  Flow  of  Water  from  a  Drill  Hole. 


CONTENTS  xi 

CHAPTER  XII 

PAGE 
VENTILATION  AND  COMPRESSED  Am 331 

Ventilation  for  Transvaal  Mines — Carbon  Dioxide  Criterion  for  Ventilation — Lack 
of  Oxygen  in  Hydraulic  Air — Wrinkles  for  Ventilating  Mine  Workings — Ventilation 
by  Suction  (by  Arthur  O.  Christensen) — Ventilating  with  Compressed  Air — Scheme 
for  Ventilating  the  Working  Face — An  Hydraulic  Air  Blast — Wing  Sail  for  Ventilating 
Shafts  (by  A.  O.  Christensen)— Ventilating  Slopes  in  Bisbee  (by  F.  W.  Holler)— Piping 
Arrangement  for  Fan  Blower — Mine  Ventilation  through  a  Drill  Hole — Ventilation 
by  Drill  Holes  (by  W.  F.  Boericke)— Self  Acting  Mine  Doors— A  Mine  Air  Door  (by 
P.  L.  Woodman) — Starting  a  Ventilating  Fan  Automatically  (by  S.  A.  Worcester  and 
J.  H.  Dietz) — Volumetric  Efficiency  of  Air  Compressors  (byF.  D.  Holdsworth) — Test- 
ing Ah-  Consumption  of  Drills — Proportions  of  Air  Mains  and  Branches — Compressor 
Precooler — Washing  Air  for  Compressors — Air  Compressor  Lubrication — Storing 
Compressed  Air  in  a  Natural  Rock  Receiver — Using  a  Pump  for  Compressing  Air — 
Reheating  Compressed  Air  with  Steam — Reheater  for  Air  Hoist — Electric  Reheaters 
—Placing  Air  Lines  in  Shafts— A  Method  of  Hanging  Air  Pipes  (by  C.  T.  Rice)— 
Stopping  Leaks  in  Air  Receivers — Pipe  Lines  as  a  Factor  hi  Rescue  Work — Water  hi 
the  Air  Line — Freezing  of  Compressed  Air  Pipe  Lines  (by  Stacy  H.  Hill) — Electric 
Heater  for  Ah*  Line  Drains  (G.  C.  Bateman). 


LIST  OF  ILLUSTRATIONS 

FIG.  PAGE 

1.  Report  Form  to  be  Punched  by  Shift  Boss 2 

2.  Labor  and  Tonnage  Charts,  Highland  Boy  Mine 9 

3.  Sanitary  Mine  Bunk 14 

4.  Sanitary  Latrine  Used  Underground  at  Goldneld  .    . ;    .- 15 

5.  The  Diamond  Hitch 18 

6.  Methods  of  Splicing  Wire  Rope • 20 

7.  Guy  Rope  Tightener  and  Anchorages  ....................  21 

8.  Fuse  Table  and  Cap  Crimper  Used  in  Joplin  District 28 

9.  Clay-filled  Box  with  Nails  Showing  Position  of  Drill  Holes 31 

10.  Method  of  Making  Tamping  Cartridges 33 

n.  Device  for  Molding  Tamping  Cartridges      . -.    .  34 

12.  Scraper  and  Loading  Tool  Used  at  Joplin ..'...- 36 

13.  Cannon  for  Opening  Chutes ; 39 

14.  Powder  House  at  the  Champion  Mine 41 

15.  Powder  Thawer 43 

16.  Powder  House  at  Traders'  Mine    .    .    . 44 

17.  A  Pick-pointed  Drill  for  Soft  Ground •  .    .    .    .  46 

18.  Drill  Made  of  Steel  Tubing 46 

19.  Designs  of  Drill  Bits ......... -.    .  49 

20.  Drill  Bits  Used  on  the  Rand 51 

21.  Hollow-steel  Bit  with  Side  Opening  . 51 

22.  North  Star  Boldess  Chuck  for  Piston  Drills ...........  52 

23.  Device  for  Shaping  Chuck  Bolts 4 53 

24.  Drill-post  Collar  without  Bolts  .    .    .    .    .    ....:.....,....        .    .  54 

25.  Drill  Column  with  Removable  Screw 55 

26.  Cast-iron  Jack  for  Drill  Column ........  56 

27.  A  Drill-twisting  Wrench 57 

28.  Cotter  Wrench  for  Stuck  Drills      57 

29.  Squirt  Gun  for  Cleaning  Drill  Holes 58 

30.  Drill  Sharpening  Plant  at  Champion  Mine      63 

31.  Pursers'  Dust  Collector 65 

32.  Aymard's  Dust  Collector 65 

33.  Dwyer  Dust-collecting  Device 66 

34.  Water  Blast  and  Draft  Inducer  for  Allaying  Dust  in  Drifts 67 

35.  Shaft  Sinking  under  Rock  Pentice 68 

36.  Details  of  Anna  Shaft  Extension 71 

37.  Plan  of  Stella  Shaft 72 

38.  Bucket  Trolley  for  Shaft  Sinking 73 

39.  An  Unusual  Two-way  Shaft 74 

40.  Shaft-timber  Ends 76 

41.  Methods  of  Framing  Shaft  Timbers      77 

42.  Framing  for  Shaft  Timbers  to  Allow  for  Additional  Compartment  78 

43.  Method  of  Timbering  the  Keystone  Shaft 79 

44.  Rogers  Shaft  Below  Concrete  Portion 80 

45.  Steel  Work  in  Concrete  Portion,  Rogers  Shaft     .    .                            •  8l 

xiii 


xiv  LIST  OF  ILLUSTRATIONS 

FIG.  PAGE 

46.  Posts  and  Square  Timbers  in  an  Inclined  Shaft 84 

47.  Shaft  Timbering  in  Swelling  Ground    .    .    .    . 85 

48.  Method  of  Supporting  Guides    .....    i    .., 87 

49.  Steel  Shaft  Sets  at  Whiteside  Mine 88 

50.  Arrangement  of  Guides  for  Drop-shaft  Sinking 89 

51.  Sections  of  Inclined  Shaft 91 

52.  Details  of  Connection  of  Concrete  Shaft  Runners  with  Wooden  Runners  of  Rock 

House 92 

53.  Shaft  Tubing  Arranged  for  Injection  of  Grouting 93 

54.  Shaft  Stations  in  Inclined  Shafts 95 

55.  General  Plan  of  Timber,  Boiler  and  Hoist  Stations,  Morning  Mine,  Mullan,  Idaho .  .     96 

56.  Arrangement  of  Skip  Pockets  at  Bunker  Hill  Mine .  r    .    .•'•'.    .     98 

57.  Skip  Pocket  at  i8oo-ft.  Level  of  Leonard  Mine,  Butte,  Mont. .    .    .    .  "."'- 99 

58.  Arrangement  of  Drill  Holes  in  Opencut  and  Tunnel  Work.    ....    .    .    .    .    .    .    103 

59.  Foot  Frame  for  Stoping  Drill 105 

60.  Machine  Set  Up  in  Inclined  Raise 107 

61.  Station  and  Timbering  in  Vertical  Raise .    . 108 

62.  Staging  Staple  and  Manner  of  Using  It • no 

63.  Drift  Set  for  Heavy  Ground no 

64.  Framing  for  Tunnel  Set in 

65.  Drift  Timbering  in  Running  Ground    .........*..... 113 

66.  Section  Along  Drift  Showing  Method  of  Placing  Sets    .    .    .    .".    .    .    .    .    *    .    .    .   113 

67.  Boom  Method  of  Timbering  in  Drifting  Through  Heavy  Ground 114 

68.  A  False  Set  for  Driving  Through  Loose  and  Heavy  Ground 115 

69.  Drift  Timbers  at  Kennedy  Mine,  Calif 118 

70.  Bridge  Sets  with  Lagging  Over  Finger  Pins *    .'    .......   119 

71.  An  Impracticable  Joint 119 

72.  Scheme  of  Back  Stoping  Employed  at  the  Dolores  Mine 122 

73.  Section  of  Stope  Showing  Diverting  Wing  Chutes 123 

74.  Robbing  Ore  Pillars 124 

75.  Stage  for  Drilling  or  Sampling  in  Stopes      ...;...   125 

76.  Arrangement  of  Holes  for  Blasting  without  Removing  Drill     .    .    .    .    .    .    .    .    .    .   126 

77.  A  System  of  Mining  on  Mesabi  Range .........   128 

78.  Ladder  Scaffold  for  Stopes 129 

79.  Method  of  Measuring  the  Stull      131 

80.  The  Stull  in  Place 132 

81.  Details  of  Square  Set  with  Round  Timbers     .    ;    .    , 133 

82.  Leaning  Stope  Sets  Used  on  Mother  Lode  .    .    > 134 

83.  Battery  Stulls  in  Calumet  &  Hecla  Stopes   .    .'. ,    .    .    . 135 

84.  End  View  of  Stope 136 

85.  Timbering  Narrow  Stopes  in  Treacherous  Ground 137 

86.  Timbering  Arrangement  for  Removing  Back  .    .    .  • 139 

87.  Plan  fo  Bulkheaded  Ore  Chute 141 

88.  Gate  for  Ore  Bin  Chutes 143 

89.  Arrangement  and  Construction  of  Underground  Grizzly 145 

90.  The  Improved  "Chinaman" 146 

91.  Standard  Ore  Chute  in  Goldfield  Cons.  Mines 147 

92.  Standard  Ore  Chute  Used  at  Nevada-Douglas  Mines 148 

93.  Chute  Gate  at  Mammoth  Copper  Mine       149 

94.  Air-hoist  Gate  for  Coarse  Ore 150 


LIST  OF  ILLUSTRATIONS  XV 

FIG.  PAGB 

95.  Finger  Chute  for  Filling  Wheelbarrows 151 

96.  Steel  Arc  Chute  at  Pittsburg-Silver  Peak  Mine 152 

97.  Elevation  of  Cananea  Bins,  Showing  Arc  Gate 153 

98.  Details  of  Metal  Part  of  Arc-type  Gate  for  Chutes ' 154 

99.  Skip  Loading  Arrangement  for  Original  Cons.  Mining  Co 155 

100.  Skip  Loading  Arrangement  at  Scranton  Mine,  Hibbing,  Minn 156 

101.  Gate  for  Skip  Loading  Chute 157 

102.  The  Whitford-Mills  Skip-loading  Device 158 

103.  Details  of  a  Steel  Ore  Pocket  in  Red  Jacket  Shaft 160 

104.  Skip-loading  Device  at  Osceola  Mine 161 

105.  Underground  Ore  Pocket 162 

106.  Plan  and  Elevation  of  Three-leg  Sheaves 163 

107.  Prospect  Headframe  at  Sand  Grass  Shaft 164 

108.  Ore  Bin  and  Headframe  for  a  Winze  Hoist 165 

109.  Arrangement  of  an  Underground  Hoist 166 

no.  The  Clermont  Headframe,  Goldfield  Cons.  Mines  Co 168 

in.  Constructional  Details  of  Tipple  Used  in  Birmingham  District 169 

112.  Structural  Details  of  the  Cananea  Ore  Bins 171 

113.  New  Orehouses  of  Tonopah  Mining  Co 172 

114.  Sections  of  Tonopah-Belmont  Or ehouse 174 

115.  Elevations  of  Tonopah-Belmont  Orehouse 175 

116.  Concrete  Storage  Bin , 176 

117.  Graphic  Determination  of  Pull  on  a  Skip  Bail 177 

118.  Chart  for  Finding  the  Proper-sized  Engine  when  the  Unbalanced  Load  and  the 

Steam  Pressure  are  Known 178 

119.  Chart  for  Determining  the  Rope  Speed  in  Hoisting 179 

120.  Chart  to  Determine  Number  of  Cars  Hoisted  per  Hour 180 

121.  Chart  for  Determining  the  Face  of  a  Grooved  Drum 180 

122.  Chart  to  Determine  the  Face,  When  the  Drum  is  Not  Grooved 181 

123.  Chart  to  Determine  the  Face,  If  the  Drum  is  Conical 181 

124.  Chart  for  Determining  the  Amount  of  Rope  Wound  on  Drum 182 

125.  Calculation  of  Power  Required  to  Haul  Cars  on  Various  Pitches 183 

126.  Some  German  Car-stopping  Devices 188 

127.  Winze  Hoist  Station  in  a  Colorado  Mine .  I91 

128.  Snatch  Block  Applied  to  Mine  Hoisting 195 

129.  Sketch  Showing  Piston  Arrangement  for  Coal  Lift 196 

130.  Device  for  Lowering  Timbers  in  Iron  Mines 197 

131.  Timber  Hoist  at  Hematite  Mine,  Ishpeming,  Mich. 198 

132.  Interchangeable  Arrangement  for  Steam  or  Electric  Hoist   ..'..' 199 

133.  A  Hoist  Friction  with  Cork  Insets -201 

134.  Continuous  Diagram  from  an  Automatic  Cutoff  Hoisting  Engine 203 

135.  Sheave  Support  in  Shifting  Ground - 205 

136.  Arrangement  of  Hoisting  Plant  at  the  Tobin  Mine 206 

137.  Idler  for  Skip  Rope  in  Shafts -207 

138.  Idler  Wheels  for  Hoisting  Ropes 207 

139.  Idler  for  Hoisting  Ropes  Used  at  Champion  Mine 208 

140.  Device  to  Prevent  Overwinding 209 

141.  Cleaning  Device  for  Flat  Wire  Cables 211 

142.  Signal  Switch  at  Baltic  Mine,  Michigan .    .  211 

143.  Spring  Switch  for  Electric  Mine  Signal 2I2 


xvi  LIST  OF  ILLUSTRATIONS 

FIG.  PAGE 

144.  German  Signaling  Device    . 213 

145.  Arrangement  of  Signal-bell  Wiring  at  Port  Henry,  N.  Y 214 

146.  Details  of  the  Ruttle  Clamp  for  Tramway  Cables      217 

147.  Nonleaking  Oiler  for  Tramway  Buckets 219 

148.  Wire-rope  Anchorage 220 

149.  Bucket  for  Drill  Steel - 222 

150.  Bucket  and  Tram  Platform 223 

151.  Iron-ore  Bucket  Used  by  Port  Henry  Iron  Ore  Co 224 

152.  Bucket  Cars  Used  in  the  Joplin  District 225 

153.  Sulphur,  Mining  and  Railroad  Co.'s  Ore  Car .226 

154.  Car  for  Tramming  Boulders,  as  Made  at  Joplin 227 

155.  Trimountain  Car  for  Stope  Filling 228 

156.  Side-dump  Car  Used  at  North  Star  Mine,  Grass  Valley,  Calif 229 

157.  Mine-car  Dumping  Cradle 230 

158.  Two-door  Car  for  Tramming  Boulders 232 

159.  Ore-car  Used  in  Main  Tunnel  of  Morning  Mine,  Ida 233 

160.  Man-  Car  for  an  Incline  Shaft 234 

161.  Details  of  the  Skip  Used  at  the  Champion  Mine 236 

162.  The  lo-ton  Skip  for  the  Franklin  Mine -.    -  238 

163.  Skip  and  Dump  Plate  Used  in  a  Minnesota  Iron  Mine 239 

164.  A  Skip  for  Flat-dipping  Shaft •    •    •  240 

165.  Automatic  Dumping  Skip  for  Winze .  241 

166.  Skip  at  Adams  Mine 242 

167.  Hiawatha  Cage  with  Skip  Attached ,  244 

168.  Safety  Catch  Used  on  the  Hiawatha  Mine  Cage • ..    .  245 

169.  Structural  Details  of  a  Light  Mine  Cage      .    < 246 

170.  Harness  for  Lowering  Mules 248 

171.  Automatic  Discharging  Bailers 249 

172.  Water  Skip  Used  at  Mineville,  N.  Y.    .    .  - 250 

173.  A  Lake  Superior  Stope-floor  Scraper .  251 

174.  A  Lumber  "Lizard" 252 

175.  Tanks  for  Wagons  for  Hauling  Fuel  Oil 253 

176.  Automatic  Bucket  Trip  .    .    . 254 

177.  Arrangement  Used  at  Kennedy  Mine  for  Dumping  Sinking  Bucket 255 

178.  Self -dumping  Bucket  Used  at  Bully  Hill  Mine .256 

179.  Automatic  Dumping  Bucket 258 

180.  Surface  Arrangement  for  Handling  Sinking  Buckets  by  Compressed  Air 260 

181.  Types  of  Skip  Dumps     .    . 261,  262 

182.  Self-dumping  Skip  at  Original  Mine,  Butte,  Mont 264 

183.  Arrangement  for  Interchanging  Skips  and  Cages  on  Leonard  No,  2  Headframe,  Butte  266 

184.  Arrangement  of  Track  for  Tipple 268 

185.  Automatic  Tipple  with  Support 268 

186.  Constructional  Details  of  Cars  and  Tipples 269 

187.  Tipple  Used  by  Witherbee,  Sherman  &  Co.,  Mineville,  N  Y .'270 

188.  Revolving  Tipple  for  Ore  Cars ..271 

189.  Car  with  Automatic  Trip 271 

190.  Snap  and  Pig-tail  Bucket  Hooks  Used  in  Joplin  Mines 273 

191.  Swivel  Hook  for  Hoisting • 273 

192.  A  Self-locking  Hoist  Hook 274 

193.  Types  of  Safety  Crane  Hooks 275 


LIST  OF  ILLUSTRATIONS  xvii 

FlG-  PAGE 

194.  A  New  Safety  Crane  Hook 276 

195.  Details  of  Hoisting-cable  Thimble 277 

196.  Safety  Crosshead  Used  at  a  Cobalt  Mine 278 

197.  Safety  Crosshead  for  Hoisting  with  Buckets 279 

198.  Crosshead  Used  on  Sinking  Bucket  in  Morning  Mine 279 

199.  Bryant  Safety  Crosshead 280 

200.  Device  for  Lowering  Bucket  Independently  of  Cage      282 

201.  A  Lake  Superior  Type  of  Mine  Cage .   .    .    . 284 

202.  Skip  Chairs  Used  in  Argonaut  Mine,  Jackson,  Calif 286 

203.  Buffer  Bars  for  Incline  Skipways 287 

204.  Tripping  Device  Used  in  Testing  Safety  Appliances  on  Cages 288 

205.  Landing  Chairs  in  Shaft 289 

206.  Landing  Chair  Used  at  Flat  River,  Mo. ........   290 

207.  Cage  Chairs . .  291 

208.  Cage  Fitted  with  Landing  Chairs 292 

209.  A  Folding  Safety  Cage     ............ 293 

210.  Safety  Device  for  Cages  ........... -. 294 

211.  Operation  of  Shaft  Gates .  294 

212.  Station  Gates  in  a  Butte  Mine   .    .    .   4    .    .    „ 295 

213.  A  Simple  Iron  Shaft  Guard    .................. 296 

214.  Extending  Track  without  Using  Short  Rails   .•  .    . 297 

215.  Method  of  Fastening  a  Guard  Rail 298 

216.  Track  and  Frog 299 

217.  One-  and  Two-way  Mine  Switches 300 

218.  Calculating  a  Crossover  Switch 301 

219.  Switch  for  Gravity  Tram 301 

220.  Double-gate  Turnout  Used  on  Mine  Tracks 302 

221.  Gravity  Switch  for  Ore  Cars . 303 

222.  The  Petersen  Switch 303 

223.  Turntable  Used  in  Highland  Boy  Mine 304 

224.  Turntable  Used  in  Some  Michigan  Copper  Mines 305 

225.  Valve  and  Column  Pipe  of  Sinking  Pump 312 

226.  Arrangement  of  Automatic  Cut-off 314 

227.  Pump  Connected  to  Airlines  for  Fire  Service 316 

228.  Timber  Set  in  Pump  Station,  Leonard  Mine,  Butte,  Mont 318 

229.  Air-lift  for  Unwatering  Shaft      321 

230.  Types  of  Mine  Eductors 322 

231.  Drainage  Scheme  from  Station  to  Suction  Pipe 326 

232.  Method  of  Cutting  Timbers 326 

233.  Draining  a  Gravity  Plane  with  Sewer  Pipe 327 

234.  Cast-iron  Gate  for  Mine  Drifts      328 

235.  Drill  Hole  and  Fittings 330 

236.  Jet  for  Ventilating  by  Compressed  Air 333 

237.  Water  and  Air-line  Connections  for  Spray 335 

238.  Convenient  Air  Blast 336 

239.  Sail  for  Shaft  Ventilating 336 

240.  Pipe  Arrangement  on  Fan  Blower  Used  on  Comstock 337 

241.  Stove-pipe  Ventilator  for  Drill  Holes 339 

242.  Self-acting  Mine  Doors  for  Double  Track  Drift  or  Tunnel 340 

243.  Details  of  Mine  Air-door  and  Catches      341 


xviii  LIST  OF  ILLUSTRATIONS 

FIG.  PAGE 

244.  Automatic  Starter  for  Ventilating  Fan , 342 

245.  Air  Tank  and  Connections.    .    f 347 

246.  A  Precooler  for  Air  Compressors 350 

247.  Concrete  Box  for  Washing  Air  .    .    ,    .    ...    . ^.    .    .    .    *.    .    .  351 

248.  Piping  from  Pump  to  Tanks  ....*.*. 352 

249.  Electric  Reheater  Used  at  Bully  Hill,  Calif 354 

250.  Old  Pipe  Supports  for  Air  Mains  .    ....  . 356 

251.  Taper  Bolt  for  Stopping  Leaks 357 

252.  Ejector  Valve  for  Air  Line      358 

253.  Piping  for  Ejecting  Valve 359 

2  54.  Electric  Heater  Used  on  Cobalt  Air  Mains      360 


I 

GENERAL  NOTES 

Economics  of  Management — Convenience  and  Protection  of   Employes 
and  Equipment — Knots  and  Ties — Miscellaneous  Notes 

ECONOMICS  OF  MANAGEMENT 

Checking  Men  In  and  Out  of  Mines. — At  the  Newport  mine,  Ironwood, 
Mich.,  where  over  1000  men  are  employed,  each  man  is  given  a  brass  tag  with 
a  number.  Each  morning  as  he  goes  to  work  he  must  appear  at  the  time- 
keeper's office  and  present  his  brass  tag,  receiving  in  exchange  a  small  card- 
board check  upon  which  is  the  date,  his  name,  number  and  occupation.  He 
keeps  this  check  during  the  day  and  returns  it  at  night  with  the  timekeeper's 
notation  on  it  showing  the  number  of  hours  worked  and  the  job  or  contract 
number,  to  wrhich  his  time  is  charged  that  day.  The  brass  check  is  returned 
to  him  when  he  presents  his  cardboard  check.  The  time  records  are  made 
up  from  these  cards.  The  system  entails  much  labor  but  no  more  than  in 
almost  any  factory  employing  a  like  number  of  men.  In  order  to  divide  the 
work  of  issuing  these  checks  at  the  office  windows,  there  are  three  aisles  leading 
to  three  office  windows;  one  for  the  surface  men,  one  for  the  numbers  ranging 
from  400  to  1000  and  a  third  for  numbers  above  1000. 

Mining  Records  (By  Frederick  T.  Rubidge). — The  collection  of  mining 
data  is  not  always  an  easy  matter  and  it  not  infrequently  happens  that  men 
who  are  good  mine  foremen  and  shift  bosses  have  little  education  and  cannot 
write  legibly,  especially  by  the  light  of  candle  and  with  the  palm  of  the  hand 
as  a  desk.  The  writing  of  the  reports  gives  an  excuse  for  a  half  hour's  leisure, 
and  it  is  customary  for  them  to  retire  to  some  convenient  place  in  order  to 
make  out  those  required  of  them,  and  this  usually  at  the  end  of  the  shift  when 
their  men  should  be  watched  and  the  holes  are  being  charged  for  blasting. 
When  thus  writing  up  his  report  from  memory  the  shift  boss  often  forgets 
just  how  many  men  he  had  in  this  or  that  working  place,  and  satisfies  himself 
by  putting  figures  down  which  will  total  properly.  And  when  this  report  is 
received  either  by  the  foreman  or  at  the  main  office  it  is  scarcely  intelligible, 
due  to  the  combination  of  errors,  smut  and  poor  writing. 

In  endeavoring  to  overcome  the  difficulties  mentioned,  I  have  successfully 
replaced  the  pencil  with  the  punch,  the  results  being  (i)  a  more  accurate 
report,  for  the  reason  that  the  punching  is  done  at  the  working  place  and 
without  inconvenience,  ($)  a  more  legible  report,  being  both  clean  and  neat, 


HANDBOOK  OF  MINING  DETAILS 


m  ?4glditioit  to  being  entirely  printed,  (3)  and  a  report  in  which,  the  duplicate 
'is  aVgbbd  aswt5ie  original.  Incidentally  the  men  take  kindly  to  the  innovation. 
Figure  i  is  a  reproduction  of  the  shift-boss  report.  The  forms  as  furnished 
to  the  shift  bosses  were  bound  into  booklets  of  50  leaves,  alternately  white  and 
light  green  in  color,  and  with  light  fiber  covers.  The  stopes  were  numbered 
according  to  the  coordinate  system.  The  coordinate  numbers  were  also  used, 
in  connection  with  the  level,  compass  point,  or  foot-  and  hanging-wall  (F.  W. 
and  H.  W.)  to  designate  the  location  of  raises  and  drifts,  punching  also  the 
word  RA ISE  or  DRIF  T  as  the  case  might  be.  M  D  stands  for  mine  development 
and  D  W  for  dead  work  as  opposed  to  mining  proper.  Under  DRILLS,  B  H 
stands  for  block-hole  drill,  H  D  for  hammer  drill,  and  P  for  piston  drill. 


JAN. 


SEP. 


DRILLS 


NO 


NO.  2 


XTRA 


FUSE 


CAPS 


LAG'NG 


HOTT 


SETT. 


T.M 


CARS 


FEB. 


OCT. 


100 


100  200 


1001200  100'200 


300 


300 


300 


APR. 


DEC. 


400 


400 


MAY 


3    500 


500 


600 


1910 


DAY 


1912 


KCT. 


FIG.    I. — REPORT   FORM   TO   BE    PUNCHED    BY    SHIFT   BOSS. 


No.  i,  No.  2  and  XTRA  refer  to  grades  of  powder.  Other  abbreviations  are 
as  follows:  S  T,  stopers;  D  R,  drill  runners;  H,  drill  helpers  (or  timbermen's 
helper  if  TIM  is  punched,  indicating  that  it  is  the  timber  boss'  report) ;  T  R, 
trammers;  T  M,  timbermen;  GRA,  grading;  M,  mucking;  TRIM,  trimming; 
PIL'R,  when  punched  in  conjunction  with  a  stope  number  is  understood  to 
be  the  pillar  adjacent  to  that  stope  on  the  north.  The  numbers  under  the 
different  classes  of  labor  and  under  drills  indicate  shifts.  For  the  labor  it 
would  be  better  to  use  hours  instead  of  shifts  as  being  more  accurate  but  in 
this  instance  it  would  have  made  the  form  too  large  for  convenient  handling 
and  punching. 

For  each  working  place  a  white  and  green  sheet  is  punched — one  operation 
serving  for  both.  The  punched  sheets  remain  in  the  book  until  the  end  of  the 
shift  when  they  are  torn  out  and  left  at  the  mine  office.  The  green  ones  are 
retained  there,  filed  in  pigeon  holes  corresponding  to  the  working  places,  and  the 
white  ones  are  sent  to  the  main  office.  Each  shift  boss  has  a  different  punch 
mark.  Any  necessary  corrections  can  be  made  by  the  mine  foreman  who  has 
an  individual  punch  mark. 


GENERAL  NOTES  3 

At  the  end  of  the  month  the  totals  for  each  working  place  are  made  up  at 
the  main  office,  according  to  these  reports,  the  stoping  being  separated  from 
the  drifting  and  raising.  The  necessary  data  regarding  the  tonnages  are 
furnished  by  the  surveyor  and  checked  with  the  hoisting  records.  The  surveyor 
also  fills  out  the  location,  dimensions,  inclination,  etc.,  of  the  various  working 
places.  Powder  is  recorded  in  sticks  but  the  explosives  unit  is  necessarily  the 
dollar.  After  the  figures  are  completed  copies  are  sent  to  the  foremen  for 
remarks,  giving  them  the  opportunity  to  explain  any  unusual  increase  in  labor 
or  explosives.  If  their  remarks  agree  with  the  facts  they  are  noted  on  the 
final  copies  which  are  distributed  to  all  in  authority.  The  punch  form  has 
also  been  used  to  advantage  in  recording  electric  haulage,  hoisting  and  pumping 
records,  and  it  is  probable  that  it  would  be  useful  in  milling  and  smelting. 

Standard  Cost  Sheets. — The  standardization  committee  of  the  Institution 
of  Mining  and  Metallurgy  on  mine  accounts  and  cost  sheets,  has  made  the 
following  recommendations1  in  regard  to  the  standardization  of  working 
accounts  and  cost  sheets.  These  recommendations  have  been  adopted  by  the 
council,  which  advises  their  use  wherever  conditions  will  permit. 

The  committee  recommended  that  for  the  sake  of  convenient  comparison, 
both  in  working  accounts  and  cost  sheets,  all  expenditure  should  be  classified 
under  the  following  main  heads:  (i)  Development.  (2)  Extraction  of  ore  (i.e., 
mining).  (3)  Sorting  at  surface,  preliminary  crushing  and  transport.  (4)  Re- 
duction costs  (i.e.,  ore  treatment).  (5)  Administration  charges  and  general 
charges  at  mine.  (6)  Realization  charges  on  products.  (7)  Taxes  and  royal- 
ties of  all  kinds,  shown  separately.  (8)  Head-office  charges. 

The  subdivision  of  these  main  heads  into  subheads  must  necessarily  depend 
somewhat  upon  the  conditions,  but  the  advantages  of  adhering  as  closely  as 
possible  to  one  form,  and  departing  from  it  only  where  necessary,  are  manifest. 
The  following  were  suggested  as  desirable  subdivisions: 

(1)  Development  costs  need  only  appear  in  the  general  cost  sheet  in  one 
total,  but  a  detailed  sheet  should  be  prepared  showing  the  total  expenditure  and 
cost  per  foot  in  shaft  sinking,  driving,  crosscutting,  raising,  winzing  and  plat 
(or  station)  cutting  separately,  as  well  as  the  proportions  of  these  expenditures 
which  are  for  labor  and  for  materials  respectively. 

(2)  Extraction  of  ore  may  be  usefully  divided  into:  (a)  Stoping  or  break- 
ing of  ore,  including  under  subheads:  compressed-air  and  rock-drill  costs,  labor 
and  supplies,  shoveling,  etc.     (6)  Timbering,  filling  excavations  and  sorting  of 
ore  in  stopes  (if  any),     (c)  Hoisting,     (d)  Pumping.     Where  the  cost  of  pump- 
ing is  exceptionally  heavy,  it  may  be  convenient  to  make  this  item  a  main 
head.     The  same  remark  applies  to  the  removal  of  the  overburden  when  a 
deposit  requires  to  be  stripped,     (e)  Underground  tramming.     (/)  Sampling, 
assaying  and  surveying,     (g)  General  underground  maintenance.     It  is  sug- 
gested that  these  subdivisions  of  the  main  head  should  be  set  out  in  detail  in 

»  Bull.  No.  76,  I.  M.  M. 


4  HANDBOOK  OF  MINING  DETAILS 

the  general  cost  sheet,  because  mining  is  at  once  the  principal  item  of  working 
cost  and  offers  the  greatest  scope  for  economies. 

(4)  Reduction   costs   should    be   subdivided   according    to   the   treatment 
undergone  by  the  ore,  e.g.,  crushing,  amalgamation,  concentration,  fine  grind- 
ing, cyaniding  sands,  slimes  treatment,  roasting,  smelting,  converting,  leaching, 
precipitation,  etc. ;  for  each  of  which  a  detail  sheet  should  be  prepared  in  such 
form  as  circumstances  may  dictate. 

(5)  Administration  may  be  divided  into  salaries  (general  resident  manager 
and  clerical  staff  on  the  spot),  stationery  and  office  general  expenses,  traveling 
expenses,   insurance   and   legal   expenses,    accidents,    medical,    sanitary   and 
hospital  expenses,  stabling  and  sundry  transport,  etc. 

(8)  Head-office  charges,  besides  ordinary  central-office  expenses,  will 
include  a  great  variety  of  items,  such  as  agency  expenses,  directors',  consulting 
engineers'  and  auditors'  fees,  bank  charges,  etc.,  also  interest  on  debentures 
(if  any).  The  individual  items  under  (5)  and  (8)  are  likely  at  times  to  merge 
one  into  the  other. 

Labor  Wasting  and  Labor  Saving  (By  S.  A.  Worcester). — The  persistent 
use  of  such  antiquated  devices  as  hand-trammed  cars  and  barrows,  shovels, 
forks,  scrapers,  rakes  and  hand-feeding  operations  of  various  kinds  in  large 
plants  operated  with  ample  capital  is  difficult  to  understand.  The  army  of 
laborers  necessary  is  always  ready  for  a  strike  whenever  the  agitator  appears, 
and  the  operation  of  the  plant  is  therefore  largely  subject  to  the  caprice  of  this 
element.  Lack  of  intelligence  is  a  most  fruitful  source  of  annoyance  and  of 
accident  to  the  laborer  and  the  plant. 

The  attitude  of  managers  toward  improvements  finds,  unfortunately,  much 
support  in  the  antiquated  designs  that  are  regularly  being  offered  and  erected 
by  machinery  builders  and  consulting  engineers.  An  instance  of  this  was  the 
recent  erection  of  several  concentrating  mills  in  which  the  concentrates  are 
shoveled  and  wheeled  from  the  table  boxes,  and,  after  drying  or  draining,  are 
again  shoveled  and  wheeled  to  box  cars  or  wagons.  One  loo-ton  mill,  recently 
designed  by  a  well-known  engineer,  requires  five  men  per  day  shift  and  four 
men  per  night  shift;  another  i5o-ton  mill  doing  exactly  similar  work,  but  using 
modern  devices  economically  arranged,  employs  but  three  men  per  day  shift 
and  two  men  per  night  shift. 

In  the  old-line  mills  referred  to,  one  man  per  shift  is  usually  employed  as 
crusher  feeder,  whereas  many  well-known  plants  eliminate  this  attendance  by 
using  either  a  simple  automatic  feeder  or  a  crusher  hopper  large  enough  to 
receive  the  mine  run.  Such  simple  and  practical  devices  as  shaking  launders, 
conveyors,  etc.,  for  moving  concentrates,  are  in  use  in  a  number  of  mills  and 
are  familiar  to  every  progressive  designer,  so  that  there  is  no  justification  for 
shoveling  and  wheeling. 

Many  cyanide  plants  employ  one  or  more  men  per  shift  filling  sand  tanks  by 
tramming  a  car  from  a  sand  bin  to  the  tanks.  Automatic  appliances  that 


GENERAL  NOTES  5 

would  save  their  cost  in  a  brief  period  of  continuous  operation  were  available 
for  this  work  when  these  mills  were  built.  Well-designed  excavator  and  con- 
veyor systems  for  handling  tailings  and  sands  were  proved  successful  a  number 
of  years  ago,  and  the  shovel  and  tram  car  are  obsolete. 

Many  managers  and  some  engineers  contend  that  automatic  machinery 
involves  necessarily  a  large  outlay,  and  is,  therefore,  prohibited  except  for  long- 
running  operations.  While  it  is  no  doubt  true  that  the  probable  life  of  the 
plant  must  determine  the  outlay  within  reasonable  limits,  yet  there  are  many 
instances  of  labor-wasting  plants  which  have  cost  more  than  completely  auto- 
matic arrangements  would  have  cost.  Automatic  devices  are  not  necessarily 
cumbersome  and  complicated.  Highly  economical  results  can  often  be  accom- 
plished by  simple  and  inexpensive  apparatus,  if  the  designer  has  the  object 
fully  in  mind. 

Mills  are  frequently  designed  so  that  a  large  sample  has  to  be  reduced  or  cut 
down  daily  by  hand.  A  large  sample  is  then  taken  to  the  assay  office  and 
recrushed  and  ground,  the  rejection  being  returned  to  the  mill.  In  nearly  all 
cases  a  laboratory  crusher  with  proper  automatic  sampling  apparatus  can  be  so 
placed  by  the  designer  that  the  sample  made  in  the  mill  is  ready  for  grinding, 
and  small  enough  for  convenient  handling,  all  rejections  being  returned  by  the 
automatic  splitter  to  the  mill.  The  work  thus  done  is  likely  to  be  more  accurate 
than  hand  work  and  the  labor  saved  is  well  worth  considering. 

In  mining  operations  the  same  disregard  for  economy  of  labor  is  evident. 
Nothing  is  more  common  than  ore  bins  so  designed  that  they  can  neither  be 
filled  to  nearly  the  full  capacity  nor  emptied  entirely  without  using  a  shovel 
or  scraper.  Hoisting  cages  are  still  being  frequently  installed  in  metal-mine 
shafts,  involving  higher  labor  and  power  costs,  greater  first  outlay  and  main- 
tenance, greater  dead  weight  and  smaller  capacity  by  far  than  the  skip,  which 
is  an  old  and  thoroughly  proved  appliance.  In  view  of  the  present  state  of 
the  art,  nothing  but  ignorance,  in  most  cases,  can  explain  this  blunder. 

The  employment  of  cages,  with  a  number  of  laborers  on  each  shift  tramming 
small-capacity  cars  from  cage  to  ore  house  or  waste  dump,  is  one  of  the  most 
common  labor-  and  power-wasting  arrangements  now  in  use.  One  skip-hoist- 
ing plant  of  my  design  displaced  four  laborers  per  shift,  a  net  saving  of  $24 
per  day,  by  replacing  cages  with  skips  dumping  into  a  motor  car  which  delivers 
the  ore  to  the  ore  house.  This  car  is  operated  by  a  motorman.  At  two  other 
plants,  where  the  motor  car  is  at  all  times  visible  from  the  engine  room,  the 
car  is  operated  by  the  engineer,  using  a  controller  placed  at  the  hoist.  At  two 
plants,  where  circumstances  favor  such  an  arrangement,  the  skip  empties  its 
load  into  a  chute  leading  direct  to  the  ore  house  and  having  deflecting  doors 
which  direct  the  ore  to  any  desired  bin. 

At  smaller  hoisting  plants,  using  the  bucket,  there  are  now  several  different 
styles  of  automatic  bucket  dumpers  in  use,  which  in  many  cases  save  one  man's 
labor  per  shift.  These  dumpers  can  be  placed  at  the  top  of  the  headframe  so 


6  HANDBOOK  OF  MINING  DETAILS 

as  to  dump  the  ore  directly  into  the  ore  house,  thereby  saving  the  wages  of  a  top 
trammer.  In  spite  of  the  evident  economy  of  these  simple  devices,  mining 
operators  are  still  frequently  erecting  labor  wasters  at  actually  a  greater  out- 
lay than  would  be  required  for  uptodate  rigs.  The  ancient  hook-and-ring 
arrangement  for  dumping  buckets  is  still  being  frequently  erected  in  places 
where  the  inexpensive  automatic  device  would  save  one  man's  wages  per  shift. 

One  favorite  argument  against  placing  the  ore  house  close  to  the  shaft,  in 
order  to  save  tramming,  is  that  the  headframe  must  usually  be  made  higher 
for  this  arrangement.  It  is  also  a  popular  belief  among  hoisting  engineers  that 
the  more  nearly  vertical  rope  pull  of  the  headframe  has  an  undesirable  effect 
on  the  hoist.  I  am  positive  that  a  careful  analysis  of  conditions  will  fully 
dispel  this  belief.  Mine  operators  seem  to  have  an  aversion  toward  head- 
frames  of  any  considerable  height,  and  when  an  extension  can  be  no  longer 
avoided  it  is  made  about  half  as  much  as  it  should  be  to  give  ample  head  room. 
As  a  rule  it  is  far  better  economy  to  gain  head  room  for  ore-handling  operations 
by  a  headframe  of  sufficient  height,  than  to  tram  a  car  from  the  shaft  over 
a  dump  or  trestle  to  a  point  where  sufficient  elevation  exists. 

An  almost  invariable  mistake  in  the  design  of  ore  houses  and  bins  is  the  prac- 
tice of  placing  the  grizzly  or  spout  which  delivers  ore  to  the  bin  at  so  low  a  height 
that  the  bin  can  be  only  partly  filled  when  the  rising  ore  chokes  the  spout. 
Then  no  further  filling  can  be  done  until  the  ore  is  shoveled  away  toward  the 
sides  and  corners  of  the  bin.  The  spout  must  be  so  placed  as  to  form  a  rock 
cone  whose  sides  slope  naturally  from  the  top  edges  of  the  bin  to  the  end  of 
the  spout,  in  order  to  fill  the  bin  to  its  capacity  without  shoveling. 

The  moss-covered  error  of  insufficient  slope  in  bin  bottoms  and  chutes 
still  prevails,  and  it  is  probable  that  fully  50%  of  all  wooden  bins  built  by 
small  operators  in  the  Rocky  mountains  have  bottoms  so  flat  that  they  cannot 
be  emptied  without  using  the  shovel.  Horizontal  bin  bottoms  are  still  being 
built  occasionally,  although  careful  consideration  of  the  working  of  this  bin 
will  nearly  always  place  it  in  deserved  disfavor. 

The  practice  of  arranging  bins  from  which  ore  is  to  be  hauled  by  wagon,  so 
that  every  pound  of  ore  has  to  be  shoveled  into  the  wagon,  is  indefensible. 
Where  the  hauling  is  to  be  done  by  contractors  and  no  lower  price  can  be 
gained  by  using  bin  gates  with  ample  height  for  saving  shoveling,  there  is  still 
the  advantage  that  having  a  convenient  arrangement  insures  better  service  than 
when  all  the  ore  must  be  shoveled.  Teamsters'  unions  sometimes  limit  the 
number  of  loads  per  day  per  man  or  team,  but  in  case  of  any  delay  the  mine 
having  spouts  and  gates  is  more  likely  to  get  its  full  number  of  loads  hauled 
than  the  one  without  such  conveniences. 

In  many  places  ore  bins  for  loading  railroad  cars  are  still  erected  with  spouts 
So  low  that  much  scraping  is  necessary  to  empty  the  bins,  and  much  shoveling 
necessary  to  trim  the  load.  If  the  bins  and  spouts  are  properly  designed 
gondola  cars  can  be  loaded  rapidly  without  the  use  of  either  shovel  or  scraper. 


GENERAL  NOTES  7 

By  using  portable  diverting  spouts,  box  cars  can  be  loaded  and  the  load  nicely 
trimmed  without  any  shoveling.  For  loading  fine  ore,  slimes  and  concentrates 
into  box  cars,  a  short  portable  conveyor  operated  by  a  small  motor  will  carry 
the  ore  from  the  bin  spout  to  the  ends  of  the  car  and  trim  the  load  without 
wheeling  or  shoveling. 

If  designing  engineers  will  adopt  as  a  cardinal  principle  the  elimination,  as 
completely  as  possible,  of  all  manual  labor  and  particularly  of  shoveling  and 
hand-tramming,  there  will  be  materially  less  encouragement  and  support  for 
managers  who  persist  in  labor- wasting  methods,  and  if  the  managers  will  exhibit, 
in  the  adaptation  of  modern  appliances  to  their  work,  a  minute  fraction  of  the 
ingenuity  and  dogged  persistence  with  which  they  at  present  defend  and  adhere 
to  their  evidently  obsolete  equipment,  labor  problems  will  be  speedily  solved 
and  net  profits  increased. 

Labor  and  Tonnage  Chart  as  Aids  in  Reducing  Costs  (By  Claude  T. 
Rice). — To  get  the  mining  costs  as  low  as  is  compatible  with  good  mining  it  is 
essential' to  instill  a  healthy  rivalry  among  the  men  and  let  them  know  that  the 
mine  superintendent,  and  every  one  in  authority  on  the  job,  knows  how  much 
work  they  are  doing.  A  great  aid  in  accomplishing  this  at  the  Highland  Boy 
mine  is  the  posting  of  labor  and  tonnage  charts  where  the  bosses  and  men  can 
see  them. 

The  tonnage  chart  shows  the  tonnage  mined  by  each  shift,  the  combined 
tonnage  of  the  two  shifts  and  the  tonnage  sent  out  over  the  tramway  (at  the 
Highland  Boy,  the  ore  is  shipped  in  that  way  from  the  mine),  the  total  number 
of  machine  drills  at  work  in  the  mine,  the  number  of  machines  working  in  ore 
and  the  number  working  in  waste.  On  the  labor  chart,  the  total  number  of 
men  employed  at  the  mine,  the  number  underground,  the  tons  mined  per  man 
employed  at  the  mine  and  per  man  working  underground  are  shown. 

The  charts  are  drawn  on  cross-section  paper  ruled  10  squares  to  the  inch  and 
a  negative  made  from  a  tracing  ruled  with  cross-section  lines.  From  the 
negative  a  print  with  white  background  and  blue  lines  is  obtained.  The  scale 
and  the  headings,  as  well  as  the  days  of  the  month,  are  put  on  the  original 
tracing  cloth  so  that  the  final  prints  are  all  ready  for  use. 

The  data  for  the  last  day  of  the  preceding  month  are  shown  as  the  start  of 
each  curve.  The  days  of  the  month  are  plotted  as  the  abscissas  and  the  other 
data  as  the  ordinates,  the  horizontal  scale  being  a  day  to  the  inch,  while  the 
vertical  scale  varies  with  the  different  curves.  The  various  curves  are  drawn 
in  with  different-colored  crayons  so  that  there  is  no  trouble  in  following  them. 

The  tonnage  curves  are  drawn  to  a  vertical  scale  of  100  tons  to  the  inch, 
as  at  the  Highland  Boy  mine  the  tonnage  does  not  fluctuate  more  than  200 
tons  per  day  and  this  scale  is  ample  to  show  with  sufficient  emphasis  the  varia- 
tions in  the  tonnage  mined  from  day  to  day.  The  shift  tonnages  are  plotted 
from  the  tonnage  reported  by  the  respective  shift  bosses  who  estimate  this  from 
the  number  of  cars  dumped  in  the  tramway  bins.  The  tramway  tonnage  is 


8  HANDBOOK  OF  MINING  DETAILS 

reckoned  from  the  number  of  buckets  sent  out  over  the  line  and  the  average 
weight  of  a  loaded  bucket  as  determined  over  a  long  period  of  time  by  checking 
it  against  the  weighed  ore  shipped  to  the  smeltery.  The  tramway  curve  is 
therefore  the  more  accurate  curve.  The  curves  reported  by  the  shift  bosses 
give  checks  on  how  full  the  cars  are  loaded  underground,  so  by  comparing  the 
curves  of  the  tonnages  mined  by  each  shift,  it  is  possible  to  see  which  is,  in  all 
probability,  failing  to  load  the  cars  properly.  At  the  Highland  Boy  mine,  the 
saving  effected  by  correcting  the  practice  of  underloading  cars,  through  the 
use  of  these  curves  has  been  greater  than  the  cost  of  keeping  them. 

Below  the  tonnage  curves,  and  on  the  same  chart  are  plotted  the  machine 
curves.  The  vertical  scale  used  on  these  is  five  machines  to  the  inch.  This 
scale  is  sufficient  to  give  emphasis  to  the  variations  in  the  number  of  machines  at 
work  which  is  usually  only  about  twenty-five.  As  one  of  the  curves  shows  the 
total  number  of  machines  running  on  ore  and  another  the  number  working  on 
waste,  and  as  most  of  the  machines  on  development  work  would  be  working  in 
waste,  an  indication  is  given  as  to  whether  the  development  work  is  being 
kept  uptodate  or  whether  it  is  being  shirked  so  as  to  make  a  tonnage  showing. 
It  might  be  well  to  show  the  number  of  machines  working  in  ore  and  the 
number  on  development  instead  of  in  waste;  as  such  a  curve  would  be 
more  important  than  the  waste  curves  unless  the  filling  were  being  broken 
underground. 

The  vertical  scale  used  on  the  curves  representing  the  number  of  men 
working  about  the  mine  is  10  men  to  the  inch.  It  might  be  well  at  mines  where 
the  square-set  method  of  mining  is  used  or  where  stull  timbering  is  done,  to 
show  how  many  men  are  working  at  timbering,  for  the  job  with  the  greatest 
possibilities  for  loafing  is  that  of  timbering.  It  always  pays  to  keep  close 
track  of  the  timbermen.  On  the  labor  chart  it  might  also  be  well  to  plot  a 
curve  showing  the  number  of  sets  or  stulls  put  in  each  day  so  as  to  keep  still 
closer  track  of  the  work  of  the  timbermen. 

On  the  tons-per-man  curves  a  vertical  scale  of  half  a  ton  to  the  inch  is  used 
so  as  to  show  plainly  the  variations.  The  importance  of  this  is  evident.  The 
drop  in  the  labor  curves  shows  clearly  which  day  of  the  month  is  pay  day,  even 
if  it  is  not  marked.  The  tons-per-man  curves  also  show  that  the  best  workers 
are  not  the  drinking  men,  although  this  increase  in  the  tons  mined  per  man  is 
due  partly  to  the  fact  that  less  development  work  is  done  on  pay  day.  At  a 
mine  where  the  stopes  are  being  filled  it  would  also  be  advisable  to  plot  a  curve, 
on  the  tonnage  chart,  showing  the  number  of  tons  or  cars  of  waste  filling  that 
is  being  dumped  into  the  stopes.  This  would  give  a  check  on  the  progress  in 
the  filling  of  the  stopes  and  the  tendency  to  let  that  important  element  in  the 
mining  lag  behind  in  the  scramble  after  ore  would  be  reduced. 

The  importance  of  these  curves  representing  graphically  the  several  steps 
in  the  operation  of  the  mine  is  evident.  They  afford,  in  a  manner  that  spurs 
the  men  on  to  do  better  work,  a  means  of  keeping  close  check  on  60  %  of 


GENERAL  NOTES 


the  total  expenditures  in  the  mining  of  the  ore.  The  curves  have  been  in  use 
at  the  Highland  Boy  mine  nearly  a  year  and  have  been  found  of  great  aid  to 
those  in  charge. 

Their  introduction  was  due  to  Ivan  DeLashmutt,  engineer  at  the  mine. 
The  set  of  curves  shown  in  Fig.  2  are  taken  from  the  charts  showing  the  details 


^'.?.>'l       284 


Tonnage 
10       1        12      13 


'-?,'.  •"' 


x— ^N 


i_^. 


^/ 


5? 


^& 


-•si". 


3 


s^r 

• 


8   9   10   11   12   13   14   15   16   17   18   19   20   21   2 


rticalScie:. 


•  — §V— 


3**' 


LI 


— 


v^ 


As 


X 


----- 


.,-': 


FIG.   2. — LABOR  AND   TONNAGE  CHARTS   SHOWING   RECORD   FOR   TYPICAL   MONTH  AT  HIGHLAND 

BOY   MINE. 

of  the  work  for  a  fairly  typical  month.     The  work  in  keeping  these  charts 
uptodate  is  small.     Charts  22  in.  wide  and  34  in.  long  are  used. 

The  Automobile  in  Mining. — The  automobile  is  doing  much  to  solve  the 
transportation  problem  in  Mohave  county,  Ariz.  A  large  auto-truck,  put  into 
use  by  the  Dixie  Queen  mine  recently,  has  been  thoroughly  tried  out  in  the  25- 


10  HANDBOOK  OF  MINING  DETAILS 

mile  haul  between  the  mine  and  Chloride  and  has  given  excellent  service. 
Loads  as  high  as  four  tons  have  been  successfully  hauled  to  the  mine  in  less 
than  half  the  time  required  by  teams. 

[Throughout  the  Western  desert  regions  the  automobile  has  proved  an 
important  factor  in  the  development  of  the  mining  industry.  The  outlying, 
and  formerly  inaccessible,  districts  have  been  brought  into  easy  communication 
with  the  centers  of  population,  thus  stimulating  and  facilitating  operations. 
The  use  of  automobile  trucks  has  also  become  extensive  in  the  mining  industry 
all  over  the  world. — EDITOR.] 

CONVENIENCE  AND  PROTECTION  OF  EMPLOYES  AND  EQUIPMENT 

Acetylene  Lamps. — The  Republic  Iron  Co.  has  been  using  acetylene  lamps 
in  its  mines  for  about  one  year.  When  the  lamps  were  first  introduced,  they 
were  sold  to  the  miners  at  the  same  price  as  the  ordinary  lamps  in  which 
"sunshine"  was  used.  After  all  the  men  had  been  supplied,  the  additional 
lamps  were  charged  out  at  75  cents  each,  which  is  the  actual  cost.  With  ordi- 
nary care  one  lamp  will  last  six  months.  The  require  1/2  Ib.  of  carbide  per 
day.  That  quantity  is  given  to  the  miner  at  the  beginning  of  each  shift,  at 
which  time  he  returns  an  empty  can  which  is  filled  during  the  day  and  thus 
is  ready  for  the  next  morning.  Each  lamp  burns  about  two  hours  before  it 
is  necessary  to  recharge.  The  lamp  is  small  and  light,  and  is  worn  on  the 
hat,  the  same  as  the  ordinary  oil  lamp.  The  great  advantage  in  the  use  of 
these  lamps  is  cleanliness.  There  is  no  oil  and  no  soot.  They  also  give  a 
better  light  and  do  not  foul  the  air  to  such  an  extent  as  some  other  illumi- 
nants.  The  acutal  cost  of  using  acetylene  lamps  is  about  one-fourth  that  of 
candles,  and  one-half  that  of  "sunshine"  or  oil. 

Some  superintendents  have  tried  to  introduce  the  acetylene  lamp  but  have 
failed;  some  of  the  excuses  are  that  the  miner  does  not  like  the  lamp;  that  it  is 
too  much  bother  to  charge  it  with  carbide  twice  a  day  underground,  and  that 
the  lamps  get  out  of  order  too  easily.  The  lamp  as  usually  constructed  is  too 
frail  for  rough  usage.  The  reflector  causes  some  trouble,  and  the  thread 
which  connects  the  carbide  chamber  with  the  water  compartment  wears  out 
easily.  These  are  mechanical  difficulties  that  the  manufacturers  can  readily 
overcome.  With  proper  care  the  lamp,  as  constructed,  will  last  a  year. 

The  Penn  Iron  Mining  Co.  has  been  using  Baldwin  acetylene  lamps  about 
two  years  at  its  mines  near  Vulcan  and  Republic,  Mich.  After  a  thorough 
trial,  the  lamps  have  proved  to  be  cheaper  than  either  candles  or  sunshine. 
They  are  much  cleaner  than  candles  or  oil,  give  a  better  light  and  burn  better 
in  poor  air. 

Candle  Tests  (By  Claude  T.  Rice).— Candle  tests  are  run  frequently  at 
mines,  but  generally  candles  of  the  same  make  are  tried — the  Granite  candle, 
a  soft  one,  against  the  hard  wax  candles,  the  Goodwin  or  the  Schneider.  There 


GENERAL  NOTES 


II 


are  several  factors  affecting  the  life  of  a  candle,  the  most  important  being  the 
condition  of  the  air.  Air  currents,  poor  ventilation,  and  hot  workings  cause 
candles  to  burn  dimly  and  unevenly,  so  all  the  material  is  not  consumed.  The 
size  of  the  candle  has  an  important  bearing  upon  the  cost  per  man,  and  often 
a  cent  per  man  can  be  saved  by  changing  the  weight. 

The  accompanying  table,  made  from  the  results  of  a  test  at  a  fairly  well  ven- 
tilated mine  of  about  the  average  temperature  for  a  deep  mine,  is  interesting  as 
showing  the  merits  of  some  new  candles  or  rather  candles  that  are  not  so  well 
known  to  western  miners,  while  it  also  brings  out  the  importance  of  the  weight 
of  the  candle  used.  Since  the  tests  were  made  the  cost  of  candles  has  been 
reduced  at  this  mine  to  3.203  cents  per  man,  using  i2-oz.  "Sunlight"  candles. 


CANDLE  TESTS 


Make  of  candle                       .  . 

Standard 
oil 

Peiry 
(hard 

Perry 
(hard 

Perry 
(hard 

Werks 
(hard 

Schnei- 
ders 

"gran- 
ite" 

wax) 

wax) 

wax) 

wax) 

(hard 
wax) 

Weight,  ounces 

12 

14 

12 

J-5 

14 

14. 

Length  of  test,  days  
Number  of  men  working  per 
day  

31 

34Sl 

i5i 

306 

J7 

322* 

26 

3o6f 

23 
366 

29 
380 

Price  per  box  at  mine 

$?     AC 

$4  64 

$4  08 

$4.36 

$c  .0^7 

$4.0^6 

Candles  used  per  man  per  day. 
Cost  per  man  per  day.  . 

4.35 

$0  062 

3.06 

$0.071 

3-94 
$0.067 

3.58 
$0.065 

3-30 

$0.0607 

3-7 
$0.0778 

CANDLE  TESTS  (Continued) 


Make  of  candle  

Good- 
wins 
(hard 
wax) 

Standard 
oil, 
No.  i 
hard 

Sunlight 
(soft 
candle) 

Sunlight 

Sunlight 

Weight,  ounces 

14 

12 

13 

13 

12 

Length  of  test,  days  

14 

16 

3° 

31 

3° 

Number   of   men  working  per 
day  
Price  per  box  at  mine 

388| 

$C  .  1C 

383f 

$4.35 

429! 

$2  .0^ 

375* 

$2  .93 

377i 

•—  •  7  ^ 

Candles  used  per  man  per  day. 
Cost  per  man  per  day  

3-5 
$0.749 

3-7 
$0.064 

3-44 
$0.0421 

3-546 

$0.0433 

3-538 
$0.0403 

12  HANDBOOK  OF  MINING  DETAILS 

Underground  Repair  Shops.— At  the  middle  working-level  stations  of  the 
shafts  of  the  Tonopah  Mining  Co.,  and  also  in  the  Goldfield  Consolidated 
mines,  repair  shops  are  maintained  for  fixing  all  air  drills  underground.  A 
machinist  is  employed  on  day  shift  to  make  these  repairs,  and  no  machines  are 
sent  to  surface  unless  there  are  some  unusual  repairs  to  be  made.  At  the 
Tonopah  mines  the  shop  is  equipped  with  a  drill  press  which  is  especially 
useful  in  boring  out  broken  stud  bolts  on  the  air  chests,  the  only  other  power- 
driven  machine  being  a  grinding  wheel.  Power  is  supplied  by  a  i-h.p.  electric 
motor. 

Abandoned  Shafts  and  Open  Cuts. — Abandoned  shafts  and  open  cuts 
should  be  kept  securely  covered  or  fenced  to  prevent  accidents  due  to  persons 
falling  into  them.  This,  however,  is  not  always  a  simple  matter,  due  to  the 
fact  that  vandals  steal  the  material  with  which  the  openings  are  covered  or 
fenced.  Only  recently  in  South  Africa  an  old  shaft  was  covered  with  timbers 
too  heavy  to  move,  and  they  were  actually  chopped  in  pieces  in  order  that  they 
might  be  carried  away.  In  another  case  a  wire  netting  had  been  placed  around 
an  open  pit  and  someone  had  deliberately  taken  the  wire  down  and  stolen  it.  In 
practically  every  mining  camp  there  are  abandoned  shafts  that  are  not  covered 
or  even  marked.  Too  much  care  cannot  be  taken  to  make  these  places  safe. 
In  the  vicinity  of  Nome,  Alaska,  there  are  dozens  of  open  shafts  on  the  tundra, 
with  nothing  to  mark  their  situation  save  the  small  pile  of  dirt  that  has  been 
taken  out.  During  the  winter  the  snow  drifts  over  these,  completely  covering 
them,  thus  making  an  excellent  trap  for  the  cross-country  traveler. 

Speaking  Tubes  in  Mines. — Speaking  tubes  are  used  for  communicating 
from  one  part  of  the  mine  to  another  in  the  Allouez  mine  in  the  Michigan 
copper  country.  They  can  be  used  up  to  distances  of  1000  ft.,  beyond  which 
the  service  is  not  satisfactory.  In  the  Allouez  mine  the  tubes  are  i  i/  2-in.  pipes. 
A  tee  is  inserted  in  the  line  wherever  it  is  desired  to  establish  a  point  from  which 
communications  can  be  sent.  The  mouthpiece  is  made  by  screwing  a  short 
nipple  into  the  tee.  The  nipple  is  closed  by  a  wooden  plug,  attached  to  a 
string  or  chain  hung  from  the  pipe  to  prevent  loss.  The  nipples  are  kept  closed 
when  not  in  use.  To  call  a  station  a  knocker,  consisting  of  a  2-in.  nipple  that 
encircles  the  i  i/2-in.  pipe  above  the  tee,  is  used.  Lifting  and  dropping  the 
knocker  on  the  tee  causes  a  sound  that  is  clearly  transmitted  by  the  pipe.  For 
greater  distances  than  800  ft.,  2-in.  pipe  should  be  used. 

Safety  Appliances  in  Mines  (By  Lee  L.  Wilcox). — It  is  the  purpose  of  this 
article  to  describe  the  various  safety  devices  used  at  the  mines  of  the  Republic 
Iron  &  Steel  Co.  They  naturally  divide  themselves  into  two  class3s;  those 
tending  to  prevent  accidents  and  minimize  the  dangers  to  which  workmen  are 
subjected,  and  those  which  relieve  suffering  and  lessen  the  attendant  dangers 
after  an  accident  has  occurred. 

The  first  class,  being  preventive,  has  occupied  most  of  the  time  and  has 
included  every  phase  of  work  about  the  mines.  It  was  started  by  the  appoint- 


GENERAL  NOTES  13 

ment  of  a  committee  from  among  the  mining  captains  and  mechanics,  whose 
duty  it  is  to  make  regular  monthly  inspection  trips,  to  report  on  the  condition 
of  the  various  mines  and  to  recommend  means  for  improving  the  conditions 
where  in  their  judgment  it  seemed  necessary.  This  committee  performs  its 
work  faithfully  and  efficiently,  and  the  result  has  been  the  extensive  adoption 
of  safety  appliances. 

This  can  be  best  described  by  citing  some  of  the  devices  employed.  In  the 
shops  all  pulleys,  belts,  gears,  and  such  equipment  are  enclosed  with  strong 
wire-cloth  guards.  Line  shafts  and  jack  shafts  are  provided  with  overhead 
walks  for  the  oilers  and  repair  men.  Hoisting  engines,  compressors,  and 
other  machines  are  protected  by  substantial  handrails  wherever  moving  parts 
may  endanger  the  employees. 

In  the  matter  of  underground  protection  the  company  is  very  particular. 
All  openings,  such  as  shafts  or  raises,  are  thoroughly  protected  by  gates,  railings 
or  bars,  making  it  practically  impossible  for  a  man  to  step  into  them  accident- 
ally. In  addition  to  this  ore  chutes  are  equipped  with  grates,  and  ladderways 
are  provided  with  permanent  platforms  at  intervals  of  about  12  ft.,  through  which 
are  left  openings  only  large  enough  to  allow  a  man  to  pass.  Ladderways  in 
hoisting  shafts  and  air  shafts  are  electric  lighted  wherever  possible,  and  no  one 
is  allowed  to  carry  a  lighted  candle  in  them,  thus  insuring  protection  against 
fire. 

The  shafts  are  equipped  with  sprinkling  devices  for  use  in  case  of  fire. 
These  are  made  by  running  a  2-in.  pipe  the  entire  depth  of  the  shaft.  To  this 
pipeline  are  connected,  at  lo-ft.  intervals,  pipes  which  extend  horizontally 
around  the  shaft  and  which  are  drilled  with  1/4  holes  at  intervals  of  4  in.  The 
stations  and  pump-rooms  in  the  mines,  where  there  is  little  water,  are  pro- 
tected in  the  same  manner.  The  places  so  protected  can  be  thoroughly 
sprinkled  in  a  short  time. 

In  dealing  with  the  second  class  of  safety  appliances,  which  have  to  do  with 
conditions  after  an  accident,  the  company  has  installed  two  complete  sets  of 
the  Draeger  rescue  apparatus,  1910  type,  one  pulmotor  and  the  necessary 
secondary  equipment  to  keep  this  apparatus  in  perfect  working  order. 

Rescue  parties  consisting  of  from  four  to  eight  men,  who  are  entirely  familiar 
with  the  underground  workings,  have  been  organized  at  each  mine.  These 
parties  are  drilled  regularly  in  the  use  of  the  apparatus.  The  drills  consist  of 
climbing  ladders,  using  picks  and  shovels,  carrying  men  and  other  such  work. 
They  are  varied  from  time  to  time  as  the  instructor  may  direct.  Together  with 
the  rescue  parties  first-aid  parties  are  organized.  The  company  has  a  physician 
at  these  meetings  to  instruct  how  to  handle  injured  men  and  how  to  apply 
bandages. 

Improvements  in  Mine  Bunks. — Proper  sanitary  conditions  and  comfort 
for  employees  should  be  seriously  considered  by  operators  in  every  line  of 
business.  Health  and  satisfaction  among  those  employed  at  a  mine  is  practi- 


14  HANDBOOK  OF  MINING  DETAILS 

cally  conducive  to  an  increased  and  steady  production.  This  has  been  given 
consideration  at  the  Sunnyside  mine,  in  Eureka  gulch,  San  Juan  county,  Colo. 
Here  the  mine  has  provided  reading  rooms,  baths  and  every  modern  con- 
venience. The  question  of  sanitary  sleeping  quarters  within  limited  space  has 
been  solved  by  the  installation  of  a  bunk,  patented  and  manufactured  by 
Charles  Scheer,  of  Silverton,  Colo.  It  is  made  up  of  piping  with  appropriate 
coupling  and  joints.  As  shown  in  Fig.  3  it  can  be  used  with  any  coil  spring.  It 
is  provided  with  side  rails  for  the  protection  of  the  occupant.  The  parts  are 
entirely  separable  and  can  be  readily  transported.  The  healthful  atmosphere 
that  prevails  in  the  sleeping  quarters  at  the  Sunnyside  mine  is  ample  proof  that 
it  fulfils  the  desired  object.  In  one  feature  alone,  the  elimination  of  the  bed 
bug,  the  installation  has  repaid  the  company. 


FIG.    3. SANITARY   MINE   BUNK   BUILT    OF   PIPE  AND    FITTINGS. 

Portable  Houses. — One  of  the  continual  problems  of  the  prospector  and 
miner  is  that  of  his  cabin.  To  a  certain  extent  this  is  being  answered  by  the 
builders  of  portable  houses.  These  range  from  7X9  ft.  to  about  18X30  ft. 
in  floor  space,  which  means  from  one  to  six  rooms.  These  houses  can  be  set 
up  or  taken  down  without  any  tools  in  three  hours,  or  less,  are  weather  proof, 
and  the  material  is  also  guaranteed  against  mildew  or  rot.  They  are  usually 
screened,  and  completely  proof  against  insects,  a  matter  of  importance  in  tropical 
or  mosquito-infested  districts.  The  weight  of  the  houses  per  square  foot  of 
floor  area  varies  from  about  4.4  Ib.  in  the  smallest  size  down  to  3.2  Ib.  in  the 
larger  sizes,  while  the  prices  range  from  about  80  cents  per  square  foot  of  floor 
area  for  the  smallest  down  to  about  65  cents  per  square  foot  for  the  largest 
size.  From  the  above  data  a  miner  knowing  about  the  size  of  house  he  desires, 
can  closely  approximate  its  weight  and  cost. 

A  Sanitary  Underground  Latrine. — The  latrine,  the  details  of  which  are 
shown  in  Fig.  4,  is  in  use  at  the  Goldfield  Consolidated  mines,  and  after  a  test 
of  several  months  has  been  found  to  be  absolutely  sanitary.  Moreover,  as  the 


GENERAL  NOTES  15 

box  closes  tight,  there  is  no  odor  of  lime  scenting  up  the  whole  level,  as  is  the  case 
when  open  boxes  are  used.  The  latrine  is  constructed  of  No.  10  sheet  iron 
and  can  easily  be  made  by  any  blacksmith.  The  top  and  bottom  are  riveted 
to  the  body,  which  is  26  in.  high  and  16  in.  in  diameter.  The  top  is  made  by 
flanging  over  a  form,  as  this  is  the  easiest  way  when  there  are  several  to  be 
made.  This  form  is  made  from  a  plate  of  3/4-in.  iron,  and  the  inside  edge  of 
the  ring  is  turned  in  a  lathe  to  an  easy  curve.  The  outer  edge  of  the  sheet 
forming  the  top  piece  of  the  box  is  flanged  2  in.,  so  as  to  stiffen  the  sides.  The 


Locking  Ecceutrltf 


FIG.   4. — SANITARY   LATRINE  USED   UNDERGROUND  AT  GOLDFEELD. 

bottom  piece  is  also  flanged  over  the  same  form.  A  flange  for  a  2  i/2-in.  pipe 
is  riveted  to  the  cylindrical  body  at  the  bottom,  into  which  a  pipe  is  screwed  for 
an  outlet.  The  outlet  is  closed  with  a  screw  plug,  as  a  valve  would  be  in  the 
way  and  liable  to  be  broken  off  when  the  latrine  is  taken  to  the  surface  to  be 
emptied.  A  hole  is  drilled  through  the  screw  plug,  and  a  pin  put  in  it  so  it 
can  be  removed  without  touching  it  with  the  hands.  Near  the  top,  on  the  oppo- 
site side  from  the  discharge,  a  flange  is  riveted  for  a  3/4-in.  pipe,  also  closed  by 
a  plug.  A  short  piece  of  pipe  extends  from  the  inside  of  the  flange,  ending  in 
an  elbow  that  is  fastened  to  a  short  nipple  pointing  down  to  the  bottom  of  the 
box.  The  cover  piece  is  a  circular  plate  of  i/2-in.  iron  in  which  a  groove  is 
cut  about  3/8  in.  deep  to  hold  a  ring  of  i/2-in.  engine  packing,  to  make  a  tight 
joint  between  the  cover  and  the  seat  of  the  latrine  when  the  cover  is  locked  in 


16  HANDBOOK  OF  MINING  DETAILS 

place.  The  cover  is  hinged  to  the  body  of  the  latrine,  and  is  locked  in  place  by 
means  of  a  bar,  fastened  at  one  end  of  the  body  by  a  link  so  that  when  the 
latrine  is  in  use  underground  it  hangs  straight  down  by  the  side,  entirely  out 
of  the  way.  On  the  other  end  in  the  top  of  the  locking  bar  is  a  notch  over 
which  slips  a  link  fastened  to  the  opposite  side.  A  small  eccentric  with  a  short 
lever  arm  is  carried  on  a  bar  for  locking  the  device. 

After  using  the  latrine,  a  little  lime  is  thrown  in  and  then  the  cover  closed 
down,  but  not  locked,  as  the  weight  of  the  lid  is  enough  to  keep  the  box  fairly 
air-tight.  The  latrine  is  placed  in  a  small  room  partitioned  off  for  the  purpose. 
Before  removing  the  latrine  the  top  is  locked  in  place.  It  is  then  loaded  on  a 
truck  and  hoisted  to  the  surface.  There  the  discharge  plug  is  removed  by 
means  of  a  wrench,  and  connection  made  between  the  washing-out  jet  at  the 
top  of  the  latrine  and  the  water  line  at  a  pressure  of  about  120  Ib.  per  square 
inch.  The  seat  is  also  washed  by  a  hose. 

Inspection  Department  of  the  Goldfield  Consolidated. — The  inspec- 
tion department  of  this  company  is  in  charge  of  the  fire-fighting  corps.  Its 
members  devote  the  entire  8-hour  day  to  inspecting  the  mine  workings,  hoisting 
engines,  hoisting  ropes,  cages  and  passages  and  ladders  used  by  men.  The 
miner  who  neglects  keeping  his  working  place  safe  is  discharged.  Records  of 
all  accidents  are  kept,  the  cause  being  specified  after  an  investigation.  The 
men  are  impressed  with  the  importance  of  attending  to  minor  injuries,  especially 
cuts,  in  order  to  avoid  septicemic  infection.  Since  the  organization  of  the 
department  in  May,  1910,  there  have  been  but  two  fatal  accidents.  The  records 
show  that  the  majority  of  the  accidents  were  due  to  falls  of  roof,  and  falls  down 
ladderways  and  chutes.  Most  of  the  ladderway  falls  were  caused  by  the  miners 
having  one  hand  employed  in  carrying  tools.  The  miners  are  encouraged  in 
every  way  to  report  dangerous  conditions,  and  are  commended  for  their  interest 
even  though  an  investigation  shows  the  report  to  be  not  well  founded. 

Goldfield  Consolidated  Fire  Equipment  (By  Claude  T.  Rice).— Since 
the  fire  in  April,  1910,  did  such  serious  damage  to  the  Goldfield  Consolidated 
mill,  the  company  has  spent  much  money  in  installing  a  comprehensive  fire- 
fighting  equipment.  As  the  square-set  method  of  timbering  is  used,  it  is 
necessary  to  keep  a  supply  of  timber  at  the  sawmill.  This  timber  is  protected 
by  several  hydraulic  monitors,  mounted  on  platforms,  high  enough  for  the 
operator  to  get  a  good  view  of  the  yard,  in  a  manner  similar  to  that  adopted  at 
most  of  the  big  sawmills  on  the  Pacific  coast.  The  monitor  used,  made  by  A.  J. 
Morse  &  Son,  is  much  cheaper  and  less  elaborate  than  most  monitors  put  on  the 
market;  it  costs  only  $15,  while  others  sell  for  about  $150.  It  has  a  2-in.  inlet 
and  i-in.  discharge  pipe.  It  discharges  about  350  gallons  per  minute  at  a  pres- 
sure of  80  Ib.  at  the  orifice,  and  has  a  range  of  about  1 50  ft. 

At  the  shaft  and  buildings  there  are  hydrants  with  lines  of  2-in.  hose  coiled 
nearby.  At  each  mine  and  at  the  mill  are  fire  stations,  where  are  kept  hose 
carts,  ladders,  a  4o-gallon  chemical  barge,  picks  and  fire  lanterns,  all  sealed  in 


GENERAL  NOTES  17 

place  to  prevent  tampering.  All  hydrants  are  kept  sealed  and  are  inspected 
about  once  a  week,  for  if  the  water  were  turned  off  at  one  of  these  places,  it 
might  take  several  minutes  to  discover  the  difficulty,  during  which  time  the 
fire  would  be  making  headway. 

As  the  floor  and  much  of  the  interior  construction  of  the  mill  are  of  wood, 
1 6  connections  for  hose  are  provided.  Under  the  ore  bins,  where  there  is  a 
possibility  of  a  fire  starting  and  gaining  headway  before  being  discovered,  a 
sprinkler  fire-extinguishing  apparatus  is  installed.  The  main  water  line  is 
carried  on  the  trestles  of  the  railroad  that  connects  the  mines  with  the  mill, 
and  there  are  numerous  hydrants  for  hose  connections  at  each  trestle.  The 
reservoir  feeding  this  system  is  on  top  of  Columbia  mountain,  and  has  a 
capacity  of  146,0x30  gallons.  There  is  a  pump  supplying  the  reservoir  at  the 
rate  of  120  gallons  per  minute  from  a  tank  holding  30,000  gallons.  The  tank 
is  replenished  at  the  rate  of  100  gallons  per  minute.  In  the  fire-prevention 
equipment  there  are  11,500  ft.  of  5~in.  pipe,  5000  ft.  of  4-in.  pipe  and  10,000 
ft.  of  2  1/2-  and  i -in.  pipe,  a  total  of  26,000  feet. 

Comparatively  speaking,  the  amount  of  water  available  for  underground 
fires  is  small.  In  contending  against  such  fires,  reliance  would  have  to  be 
placed  upon  bulkheads,  so  placed  as  to  keep  the  fire  within  a  restricted  area. 
The  mines  are  inspected  after  each  shift  for  the  discovery  of  incipient  fires.  At 
each  mine  there  are  two  Drager  helmets. 

KNOTS  AND  TIES 

The  Diamond  Hitch  (By  W.  H.  Storms).— There  are  many  things  that 
prospectors  should  know  in  addition  to  a  knowledge  of  minerals  and  formations 
and  how  to  hit  a  drill,  and  one  of  the  most  useful  of  the  others  is  how  to  "  throw 
the  diamond  hitch."  The  diamond  hitch  is  used  to  secure  a  pack  on  the  back 
of  an  animal  in  such  manner  that  the  rope  at  the  top  of  the  pack  forms  a 
diamond,  and  is  the  most  satisfactory  way  to  fasten  a  pack  that  has  been 
devised. 

The  first  essential  is  a  good  pack  saddle,  to  which  are  attached  back  and 
breast  straps  to  keep  the  load  from  shifting  on  steep  hills.  The  next  essential 
is  a  strong  rope.  A  5/8-in.  manila  is  good,  but  a  rawhide  lariat  is  better  if  it  is 
not  too  new  and  stiff.  First  secure  the  pack  saddle  on  the  animal,  and  be  sure 
that  it  is  secure,  for  pack  animals  soon  become  tricky  and  will  swell  up  by 
holding  their  breath  while  the  saddle  is  being  cinched.  To  beat  this  draw  the 
straps  tight  and  pretend  to  make  them  fast,  watching  the  animal,  and  when  the 
breath  is  exhaled,  quickly  take  up  the  slack. 

When  the  pack  saddle  is  securely  cinched  the  various  articles  of  the  pack 
may  be  placed  on  the  back  of  the  animal,  being  held  in  place  by  preliminary 
lashing,  good  enough  to  hold  temporarily.  After  all  is  in  place  you  are  ready 
for  the  diamond  hitch.  This  requires  two  men,  one  on  each  side  of  the  animal. 


i8 


HANDBOOK  OF  MINING  DETAILS 


He  on  the  left  is  the  thrower;  he  on  the  right  of  the  animal,  the  cincher.  The 
thrower  first  ties  one  end  of  the  pack  rope  securely  to  a  ring  attached  to  a  broad 
leathern  cinch,  as  at  A  in  Fig.  5.  The  other  end  of  this  cinch  is  equipped  with 
a  hook  B.  Having  made  the  rope  fast,  the  thrower,  holding  the  rope  and  ring 
end  of  the  cinch  in  his  left  hand,  tosses  the  hook  end  of  the  cinch  under  the 
animal's  belly,  where  it  is  caught  by  the  cincher  with  his  left  hand.  The  latter 
now  stands  ready  to  use  his  right  hand  when  his  partner  throws  him  the  loop  C 
over  the  back  of  the  animal.  The  loop  is  quickly  caught  in  the  hook,  and  the 
thrower  adjusts  the  rope  so  as  best  to  secure  the  various  articles  of  the  pack, 


Cinch 


Head 


Tail 


-Cinch 


FIG.    5. — THE   DIAMOND    HITCH. 

while  following  the  lines  shown  in  the  sketch.  The  cincher  now  draws  the  long 
end  of  the  rope  tight,  and  throws  the  loose  end  forward  over  the  back  of  the 
animal  to  the  thrower,  and  together  they  adjust  the  rope  to  the  pack,  while 
keeping  the  loose  end  taut.  A  turn  is  taken  beneath  the  rope  at  D,  and  it  is 
then  carried  forward  and  around  the  lower  corner  of  the  pack  at  E,  and  back- 
ward along  the  lower  side  of  it  toward  F,  where  it  is  taken  upward  to  the  top 
and  a  second  turn  taken  at  G.  From  there  it  is  passed  around  the  back  and 
upper  comer  at  H,  down  to  7  and  around  that  corner,  and  forward  along  the 
lower  right-hand  side  of  the  pack  to  /,  upward  and  around  the  corner  at  K  and 
looped  under  at  L;  thence  forward  and  downward  to  M,  and  along  the  lower 


GENERAL  NOTES  19 

left-hand  side,  where  a  turn  can  be  taken  in  the  crossing  rope  at  JV,  and  the 
loose  end  secured  in  the  diamond  at  the  top  of  the  pack. 

Throughout  this  entire  performance  the  rope  must  be  kept  as  tight  as  pos- 
sible, and  the  end  secured  so  it  will  not  slip.  The  diamond  hitch  is  quickly 
undone,  once  the  end  is  loosened,  for  there  is  no  portion  of  it  that  binds,  or 
works  into  hard  knots. 

Splicing  Wire  Rope. — Wire  rope  is  susceptible  of  almost  perfect  splicing 
and  the  operation  is  so  simple,  states  F.  L.  Johnson  in  Power,  that  it  may  be 
learned  in  an  hour  by  any  mechanic  who  is  at  all  skillful  in  the  use  of  ordinary 
tools.  For  all  kinds  of  transmission  rope  the  long  splice  is  used  and  should 
not  be  less  than  16  ft.  in  length  for  i/2-in.  rope  and  increasing  to  30  ft.  for  the 
larger  sizes.  Where  the  splicing  must  be  done  in  position,  rope  blocks  are  used 
to  draw  the  wire  taut,  as  in  Fig.  i,  care  being  taken  to  make  fast  far  enough 
from  the  ends  to  leave  plenty  of  room  for  the  splice  and  the  men  who  make  it. 
If  possible,  it  is  better  to  hold  the  rope  taut,  mark  the  splice  on  both  ends,  by 
securely  winding  with  No.  20  annealed-iron  wire,  throw  it  off  the  sheaves  and 
make  the  splice  on  the  floor  or  staging,  as  may  be  most  convenient.  The 
strands  of  both  ends  are  unlaid,  back  to  the  points  wound  with  wire,  the  hemp 
core  cut  off  and  the  ends  of  the  rope  brought  together  with  the  strands  inter- 
laced, as  shown  in  Fig.  2.  Any  strand,  as  a,  Fig.  3,  is  now  unlaid  and  closely 
followed  by  the  corresponding  strand  i  of  the  other  end  of  the  rope  which  is 
pressed  closely  into  the  groove  left  by  the  unlaid  strand.  The  unwinding  of  one 
strand  and  the  inwinding  of  the  other  are  continued  until  all  but  about  1 2  in.  of 
strand  i  is  laid  in,  when  a  is  cut  off  at  the  same  length  and  both  strands  securely 
tied  with  cord.  Strands  4  and  d  are  next  treated  in  the  same  way  and  the  pro- 
cess is  repeated  with  each  pair  of  strands  until  all  are  laid  and  cut,  the  projecting 
ends  being  tied  as  shown  in  Fig.  4  to  prevent  unwinding.  When  this  has  been 
done  the  splice  is  bent  and  worked  in  all  directions  until  the  tension  in  all  the 
strands  is  equal  and  the  rope  as  flexible  there  as  elsewhere.  If  this  is  not  done 
and  there  is  more  tension  in  some  of  the  strands  than  in  others  when  a  stress  is  put 
on  the  rope,  these  strands  will  pull  into  the  rope,  making  a  bad  looking  and 
weak  splice.  Next,  the  open  or  free  ends  of  the  12  strands  are  carefully  trimmed 
and  wound  with  fine  wire.  Two  rope-and-stick  clamps,  Fig.  5,  are  now  secured 
to  the  rope,  one  on  each  side  of  an  end  crossing,  as  in  Fig.  8,  for  the  purpose 
of  untwisting  the  rope  to  allow  tucking  the  strand  ends  into  the  middle  of  the 
rope.  There  are  two  ways  of  tucking  in  these  ends.  They  are  first  straightened 
with  a  mallet;  the  long  ends  of  the  rope-clamp  handles  are  twisted  in  opposite 
directions,  separating  the  strands  and  exposing  the  hemp  core,  which  is  cut 
off  and  pulled  out  between  the  points  to  which  the  tucked-in  strands  will 
reach  and  the  ends  forced  into  the  place  formerly  occupied  by  the  core.  This 
is  most  easily  done  with  the  aid  of  a  marlin  spike,  which  is  passed  over  the  strand 
that  is  to  be  tucked  and  under  two  strands  of  the  rope,  Fig.  6,  and  moved 
along  the  rope  spirally  following  the  lay  and  forcing  the  free  end,  as  shown  in 


2O 


HANDBOOK  OF  MINING  DETAILS 


Fig.  7,  into  the  core  space.  In  the  other  method  the  strands  are  more  widely 
separated  by  untwisting  the  rope  with  the  clamps,  Fig.  9,  slipping  the  free  end 
between  the  strands  and  correcting  slight  kinks  by  the  use  of  a  mallet.  The 
order  in  which  the  ends  are  tucked  in  is  immaterial.  Some  operators  prefer  to 


FIG.    6. — METHODS   OF   SPLICING   WIRE    ROPE. 


tuck  all  the  ends  pointing  in  one  direction  before  any  of  those  pointing  the 
opposite  way,  while  others  finish  each  pair  of  ends  in  series.  If  the  foregoing 
directions  are  intelligently  followed  the  splice  will  be  uniform  with  the  rest  of  the 
rope,  of  nearly  equal  strength  throughout,  and  after  a  few  hours'  use  it  will  be 


GENERAL  NOTES 


21 


almost  impossible  to  detect  the  splice.     Four-strand  hemp  ropes  can  be  spliced 
in  the  same  way,  this  splice  being  known  among  riggers  as  the  long  splice. 


Ji-in.  Pipe  4-in.  long 


Details  of  Guy  Rope  Tightener 


18-h 


J  d 

« 7-tn.— >] 


f^ 


H-in.  Round  Iron 


4-ftr 


H 

Iron  Parts  of  Concrete  Anchorage 


FIG.    7. GUY-ROPE   TIGHTENER  AND  ANCHORAGES. 

A  Guy-rope  Tightener.— In  Fig.  7  are  shown  the  details  of  a  guy-rope 
tightening  device  which  is  used  in  the  southwestern  Missouri  zinc  district.  The 
tightening  device  resembles  a  buckle  in  construction.  It  is  made  of  i/2-in. 


22  HANDBOOK  OF  MINING  DETAILS 

wrought  iron,  with  a  piece  of  pipe  over  the  broad  end  of  the  buckle-shaped  link 
so  as  to  allow  the  tongue  to  rotate  readily  without  much  friction.  This  tightener 
is  fastened  to  the  anchor  of  5/8-in.  wrought  iron  after  the  guy  rope  has  been 
secured  to  the  tongue  of  the  tightener.  By  using  the  tongue  as  a  lever,  the  guy 
line  is  wound  around  the  broad  end  of  the  buckle  until  the  proper  tension  has 
been  obtained.  Then  the  tongue  is  locked  by  hooking  its  end  over  the  buckle 
part  of  the  tightener.  The  iron  parts  for  a  concrete  anchorage  in  which  a  pipe 
cross  piece  is  used  are  also  shown. 

MISCELLANEOUS  NOTES  . 

Disposal  of  Waste. — In  the  stripping  of  the  large  ore  deposits  on  the  Mes- 
abi  range,  the  disposal  of  the  overburden  is  one  of  the  large  problems  that  has 
to  be  solved.  In  most  cases  this  waste  material  is  hauled  from  i  to  2  miles  in 
side-dump  cars  and  emptied  over  the  side  of  a  dump,  50  to  100  ft.  high.  The 
shifting  of  the  standard-gage  track  to  keep  up  with  the  growth  of  the  dump  is 
a  matter  of  considerable  expense.  In  nearly  all  cases  this  shifting  is  accom- 
plished by  hand  labor.  At  one  or  two  mines  it  is  done  with  the  wrecking  car 
by  simply  attaching  four  chains  to  3o-ft.  sections  of  track,  lifting  them  bodily 
and  setting  them  over  the  required  distance.  At  one  mine  a  track  shifter  is 
being  tried.  Where  there  is  ample  room  and  no  danger  of  damage  suits 
arising,  the  latest  device  is  to  use  water  to  wash  the  material  from  the  railroad 
tracks.  The  necessary  requirements  are  a  high  bank  upon  which  to  build  a 
15-  or  2o-ft.  trestle,  and  a  deep  gulch  in  which  to  deposit  the  dirt.  A  substan- 
tial trestle  is  constructed  and  this  is  filled  up  to  the  ties  with  dirt  from  the  dump 
cars.  Just  beneath  the  ties  and  on  the  outside  row  of  posts  is  placed  a  6-in. 
water  pipe  with  i/2-in.  holes  in  one  side,  18  in.  apart.  These  holes  all  open  out 
from  the  track.  The  bottom  of  the  trestle  is  buried  sufficiently  deep  to  hold 
it  in  place  and  there  is  little  danger  of  its  washing  out.  The  material  is  dumped 
over  the  side  of  the  trestle  from  the  cars  and  the  water  plays  upon  it,  washing  it 
down  the  slope  to  the  low  ground.  In  this  way  the  angle  of  repose  for  the  dirt 
will  be  10  or  15°  instead  of  approximately  40°.  In  the  case  under  consideration 
the  track  is  about  7  5  ft.  above  the  side  of  a  small  lake.  This  flat  alluvial  fan  will 
extend  out  a  long  distance  and  add  largely  to  the  capacity  of  the  dump.  In  this 
way  a  solid  track  can  be  maintained  and  it  need  only  be  moved  once  in  many 
months,  whereas,  in  the  usual  scheme  it  is  necessary  to  shift  the  track  almost 
daily.  The  shifting  operation  is  expensive  and  in  addition  the  track  is  always  in 
bad  condition. 

Mine  Tailings  for  Filling  (By  Lucius  L.  Wittich). — While  the  use  of 
mine  tailings  as  railroad  ballast  is  not  new,  the  method  employed  by  the  St. 
Louis  &  San  Francisco  R.  R.  Co.,  west  of  Joplin,  Mo.,  is,  I  believe,  novel.  The 
tailings  were  introduced  into  abandoned  and  dangerous  zinc  and  lead  workings 
directly  beneath  the  railroad  right-of-way  through  four  8-in.  drill  holes  put 


GENERAL  NOTES  23 

down  from  the  surface  to  penetrate  the  drifts,  140  ft.  beneath.  Hopper-shaped 
excavations  were  made  at  the  top  of  each  drill  hole,  the  holes  having  been  sunk 
between  the  rails  of  the  track  about  20  ft.  apart.  More  than  16,000  cu.  yd. 
of  mine  gravel  were  used  in  filling  the  old  drifts,  the  greatest  volume  put  through 
a  single  hole  having  been  in  excess  of  9000  cu.  yd.  That  the  tailings  might  be 
equitably  distributed  and  made  compact,  streams  of  water  from  two  2-in. 
pumps  were  poured  into  the  hoppers,  the  water  carrying  the  tailings  through  the 
drill  holes  and  spreading  them  through  the  drifts.  As  a  precautionary  measure, 
to  prevent  the  tailings  spreading  over  too  wide  an  area,  the  ground  of  the  old 
workings,  at  certain  points  where  it  connected  with  other  drifts,  was  shot  down 
and  these  barriers  acted  as  walls  which  stopped  the  promiscuous  distribution  of 
the  waste  chat,  but  which  were  porous  enough  to  permit  the  big  volume  of 
water  escaping  into  other  drifts,  from  which  it  was  pumped  again  through  the 
pumps  that  had  been  stationed  in  the  mine. 

Strength  of  a  Mine  Dam. — The  total  pressure  exerted  by  water  on  a  dam 
is  found  by  multiplying  the  wetted  area  of  the  face  of  the  dam,  expressed  in 
square  feet,  by  62  1/2,  the  weight  in  pounds  of  i  cu.  ft.  of  water,  and  this  prod- 
uct by  the  vertical  height  of  the  surface  of  the  water  above  the  center  of  gravity 
of  the  wetted  area,  says  Coal  Age.  To  calculate  the  required  thickness  of  a 
dam,  let 

/=  Thickness  of  dam  (in.); 

r=  Shorter  radius  of  dam  (in.); 

w=  Width  of  opening  or  span  (in.); 

p= Pressure  of  water  at  dam  (Ib.  per  square  inch); 

S=  Compressive  strength  of  material  (Ib.  per  square  inch). 
For  an  arched  dam 


The  shorter  radius  of  the  dam  should  be  from  one-fourth  to  one-third  greater 
than  the  clear  span  or  width  of  opening.  For  practical  reasons,  it  would  not  be 
advisable  to  build  a  dam  less  than  20  in.  thick. 


II 

EXPLOSIVES 

Blasting  and  Handling  of  Dynamite— Storage  of  Explosives — 
Frozen  Dynamite. 

BLASTING  AND  HANDLING  OF  EXPLOSIVES 

"Don'ts"  in  Using  Explosives. — The  following  "Don'ts"  were  embodied 
in  a  lecture  on  explosives,  delivered  recently  by  A.  E.  Anderson  before  the  mining 
men  of  Telluride,  Colo.  While  many  of  them  are  by  no  means  new,  occasional 
repetition  is  not  undesirable;  if  properly  observed,  fewer  dispatches  headed 
"Blown  up  While  Thawing  Frozen  Dynamite,"  etc.,  would  be  seen. 

Don't  forget  the  nature  of  explosives,  but  remember  that  with  proper 
care  they  can  be  handled  with  comparative  safety. 

Don't  smoke  while  handling  explosives,  and  don't  handle  explosives  near 
an  open  light. 

Don't  shoot  into  explosives  with  a  rifle  or  pistol,  either  in  or  out  of  a 
magazine. 

Don't  leave  explosives  in  a  field  or  any  place  where  cattle  can  get  at 
them.  Cattle  like  the  taste  of  the  soda  and  saltpeter  in  explosives,  but  the 
other  ingredients  would  probably  make  them  sick  or  kill  them. 

Don't  handle  or  store  explosives  in  or  near  a  residence. 

Don't  leave  explosives  in  a  wet  or  damp  place.  They  should  be  kept  in 
a  suitable,  dry  place,  under  lock  and  key,  and  where  children  or  irresponsible 
persons  cannot  get  at  them. 

Don't  explode  a  charge  to  chamber  a  bore  hole  and  then  immediately  re- 
load it,  as  the  bore  hole  will  be  hot  and  the  second  charge  may  explode 
prematurely. 

Don't  do  tamping  with  iron  or  steel  bars  or  tools.  Use  only  a  wooden  tamp- 
ing stick  with  no  metal  parts. 

Don't  force  a  primer  into  a  bore  hole. 

Don't  explode  a  charge  before  everyone  is  well  beyond  the  danger  zone 
and  protected  from  flying  debris.  Protect  the  supply  of  explosives  also  from 
danger  from  this  source. 

Don't  hurry  in  seeking  an  explanation  for  the  failure  of  a  charge  to 
explode. 

Don't  drill,  bore  or  pick  out  a  charge  which  has  failed  to  explode.  Drill 
and  charge  another  bore  hole  at  least  2  ft.  from  the  missed  one. 

24 


EXPLOSIVES  25 

Don't  use  two  kinds  of  explosives  in  the  same  bore  hole  except  where  one 
is  used  as  a  primer  to  detonate  the  other,  as  where  dynamite  is  used  to  detonate 
Judson  powder.  The  quicker  explosive  may  open  cracks  in  the  rock  and  permit 
the  slower  to  blow  out  through  these  cracks,  doing  little  or  no  work. 

Don't  use  blasting  powder,  permissible  explosives  or  high  explosives  in 
the  same  bore  hole  in  coal  mines. 

Don't  use  frozen  or  chilled  explosives.  Most  dynamite,  except  Red 
Cross,  freezes  at  a  temperature  between  45°  F.  and  50°  F. 

Don't  thaw  dynamite  on  heated  stoves,  rocks,  sand,  bricks  or  metal  or  in 
an  oven,  and  don't  thaw  dynamite  in  front  of,  near  or  over  a  steam  boiler  or 
fire  of  any  kind. 

Don't  take  dynamite  into  or  near  a  blacksmith  shop  or  near  a  forge  on 
open  work. 

Don't  put  dynamite  on  shelves  or  anything  else  directly  over  steam  or 
hot  water  pipes  or  other  heated  metal  surface. 

Don't  cut  or  break  a  dynamite  cartridge  while  it  is  frozen,  and  don't  rub 
a  cartridge  of  dynamite  in  the  hands  to  complete  thawing. 

Don't  heat  a  thawing  house  with  pipes  containing  steam  under  pressure. 

Don't  place  a  hot- water  thawer  over  a  fire,  and  never  put  dynamite  into 
hot  water  or  allow  it  to  come  in  contact  with  steam. 

Don't  allow  thawed  dynamite  to  remain  exposed  to  low  temperature 
before  using  it.  If  it  freezes  again  before  it  is  used  it  must  be  thawed  again. 

Don't  allow  priming,  the  placing  of  a  blasting  cap  or  electric  fuse  in  dyna- 
mite, to  be  done  in  a  thawing  house  or  magazine. 

Don't  prime  dynamite  cartridges  or  charge  or  connect  bore  holes  for  elec- 
tric firing  during  the  immediate  approach  or  progress  of  a  thunder  storm. 

Don't  carry  blasting  caps  or  electric  fuses  in  wearing  clothes. 

Don't  tap  or  otherwise  investigate  a  blasting  cap  or  electric  fuse. 

Don't  attempt  to  take  blasting  caps  from  the  box  by  inserting  a  wire, 
nail  or  other  sharp  instrument. 

Don't  try  to  withdraw  the  wires  from  an  electric  fuse. 

Don't  fasten  a  blasting  cap  to  the  fuse  with  the  teeth  or  by  flattening  it 
with  a  knife ;  use  a  cap  crimper. 

Don't  keep  electric  fuses,  blasting  machines  or  blasting  caps  in  a  damp 
place. 

Don't  attempt  to  use  electric  fuses  with  the  regular  insulation  in  un- 
usually wet  work.  For  this  purpose  secure  special  waterproof  fuses. 

Don't  worry  along  with  old,  broken  leading  wire  or  connecting  wire.  A 
new  supply  won't  cost  much  and  will  pay  for  itself  many  times  over. 

Don't  handle  fuse  carelessly  in  cold  weather,  for  when  cold  it  is  stiff  and 
breaks  easily. 

Don't  store  or  transport  blasting  caps  or  electric  fuses  with  high 
explosives. 


26  HANDBOOK  OF  MINING  DETAILS 

Don't  store  fuse  in  a  hot  place,  as  this  may  dry  it  out  so  that  uncoiling  will 
break  it. 

Don't  "lace"  fuse  through  dynamite  cartridges.  This  practice  is  fre- 
quently responsible  for  the  burning  of  the  charge. 

Don't  operate  blasting  machines  half-heartedly.  They  are  built  to  be  ope- 
rated with  full  force.  They  must  be  kept  clean  and  dry. 

Don't  cut  the  fuse  short  to  save  time.     It  is  dangerous  economy. 

Don't  expect  explosives  to  do  good  work  if  it  is  attempted  to  explode 
them  with  a  detonator  of  insufficient  strength. 

Preparations  for  Blasting  (By  M.  T.  Hoster). — In  almost  every  one  of  the 
various  mines  and  mining  districts  of  the  country  some  peculiarity  in  the  pro- 
cedure of  the  miner  in  firing  his  round  of  holes  may  be  observed.  The 
necessary  operations  are  discussed  under  the  subheads  following,  and  the  best 
practice  outlined. 

Cutting  the  Fuse. — Fuse  should  never  be  less  than  5  ft.  in  length  and  often 
6  or  7  ft.,  depending  on  the  number  of  holes,  whether  in  a  shaft,  raise,  drift  or 
stope.  It  should  always  be  cut  straight  across  (not  slanting)  with  a  sharp  knife 
or  cleaver,  for  if  the  fuse  is  not  so  cut,  some  of  the  powder  may  fall  out  or  the 
pointed  end  may  bend  over  and  seal  the  powder  from  the  fulminate  when  the 
fuse  is  pushed  into  the  cap. 

Crimping. — Crimping  the  cap  on  the  fuse  is  usually  done  with  a  crimper, 
the  teeth  or  a  knife.  Crimping  caps  with  a  knife  or  the  teeth  is  not  only  dan- 
gerous but  ineffective  and  is  often  responsible  for  expensive  misfires.  With 
the  thin-jawed  crimper,  the  cap  is  grooved  on  the  fuse,  the  great  disadvantage  of 
this  being  that  such  a  sharp  groove  may  often  squeeze  the  shell  into  the  fuse 
so  closely  that  the  powder  train  is  choked  or  cut,  causing  a  missed  hole.  Two 
or  more  such  grooves  may  be  lightly  pressed  on  each  cap,  but  water  may  leak 
in  as  the  cap  does  not  fit  the  fuse  closely. 

The  broad-jawed,  or  California  crimper  is  far  better,  as  the  metal  is  not 
grooved  and  still  fits  the  fuse  closely.  With  the  California  crimper,  the  cap 
should  be  pressed  several  times,  revolving  the  fuse  and  cap  slowly  each  time  the 
jaws  open,  squeezing  lightly  at  first  and  stronger  as  the  cap  contracts  about  the 
fuse.  This  crimp  gives  a  water-tight  fit.  Many  missed  holes  are  unquestion- 
ably due  to  imperfect  crimping;  hence  this  operation  should  be  left  to  a  reliable 
man  and  not  merely  to  the  miner. 

The  Primer. — At  times,  one  will  see  a  miner  loading  his  holes  by  tamping  in 
a  stick  or  two  of  powder,  then  inserting  the  fuse  and  tamping  in  more  powder, 
the  fuse  lying  between  the  wall  of  the  hole  and  the  powder.  This  is  inefficient. 
A  primer  should  always  be  prepared  beforehand.  The  best  two  methods  of 
making  a  primer  are:  (i)  Open  up  one  end  of  the  cartridge,  extract  a  small 
amount  of  powder,  press  a  hole  into  the  center  of  the  stick  of  powder  and  insert 
the  fuse.  Then  twist  the  paper  cartridge  about  the  fuse  and  tie  it  tightly  with 
cord.  For  wet  holes  the  space  at  the  top  of  the  cartridge  is  often  filled  with 


EXPLOSIVES  27 

grease.  (2)  Simply  stick  a  hole  into  the  cartridge  and  insert  the  fuse.  This 
method  does  not  require  as  much  time  and  is  not  as  good  as  the  first,  but  will 
give  satisfactory  results.  This  primer  must  be  handled  with  care  to  prevent  the 
fuse  from  coming  out  and  should  always  be  inserted  into  the  hole  fuse-end  first, 
which  necessitates  a  bend  in  the  fuse  and  there  is  a  possibility  of  this  nicking  the 
fuse  and  causing  a  misfire. 

Greasing. — For  wet  holes  the  fuse  is  often  greased  with  axle  grease  or  crude 
oil.  Some  miners  rub  grease  into  the  entire  fuse,  but  this  is  not  necessary,  as 
any  good  fuse  will  withstand  water  for  a  few  hours  at  least.  If  grease  is  used  at 
all  it  should  be  rubbed  on  the  fuse  only  where  it  enters  the  cap  so  as  to  prevent 
water  from  soaking  into  the  cap  at  that  point. 

Loading  the  Holes. — For  dry  holes,  all  of  the  paper  cartridges,  excepting 
the  primer  cartridge,  should  be  slit  with  a  knife  before  placing  in  the  hole.  The 
object  of  this  is  to  give  the  powder  a  chance  to  spread  out  when  tamped  and  so 
fill  the  entire  hole.  For  wet  holes  it  is  best  to  slit  the  first  two  cartridges  only, 
as  the  water  will  fill  up  any  space  not  taken  up  by  the  remaining  powder.  The 
most  effective  place  to  have  the  powder  is  at  the  bottom  of  the  hole,  hence  the 
object  of  slitting  at  least  the  first  two  sticks.  In  loading  a  hole  with,  for  example, 
five  sticks  of  powder,  put  in  the  first  two  sticks,  tamping  each  solidly  into  place. 
Then  put  in  the  primer,  tamping  but  lightly,  and  finally  the  last  two  sticks  of 
powder,  which  should  be  pressed  in  well.  Some  miners  say  to  load  the  primer 
last,  but  this  hardly  seems  advisable.  Never  load  the  primer  first,  and  always 
use  a  wooden  tamping  stick. 

Tamping  with  Clay  or  Mud. — In  some  districts  soft  clay  or  mud  is  tamped 
into  the  hole  after  the  powder  has  been  loaded  but  whether  there  is  any  good 
resulting  from  this  tamping  is  doubtful.  It  is  often  advantageous  to  force  a 
little  earthy  matter  into  a  hole  in  order  to  prevent  the  sparks  of  some  nearby 
hole  from  igniting  the  powder  or  to  prevent  the  powder  in  a  dry  hole  from  falling 
out,  but  otherwise  the  force  of  the  explosion  can  hardly  be  affected  by  this 
tamping.  If  a  hole  is  tamped  at  all  it  should  never  be  filled  to  the  collar,  as  this 
makes  it  difficult  to  discover  a  missed  hole. 

Splitting  and  Spitting  the  Fuse. — Each  fuse  to  be  spit  should  be  cut  open 
at  or  near  the  end  so  as  to  expose  sufficient  fuse  powder  for  igniting.  The  three 
general  ways  in  which  this  may  be  done  are:  Slice  the  last  inch  of  the  fuse  in 
half;  cut  a  slit  in  the  side  of  the  fuse;  fork  open  the  end  of  the  fuse.  The  first 
is  a  poor  way,  as  the  powder  exposed  may  all  fall  out  before  it  is  time  to  spit. 
The  second  method  is  much  used  as  there  is  the  least  chance  of  the  powder  falling 
out  and  it  requires  little  time.  The  chief  disadvantage  to  this  method  is  that 
when  spitting,  the  fire  may  travel  away  from  instead  of  toward  the  cap,  and  the 
miner,  being  in  a  hurry,  may  not  notice  this.  The  last  method  is  undoubtedly 
the  best,  for  although  some  of  the  fuse  powder  may  fall  out,  enough  will  always 
be  left  where  the  arms  of  the  fork  meet.  For  very  wet  places  the  second  method 
has  an  advantage  over  the  third  in  that  the  powder  is  not  as  likely  to  become  wet. 


28 


HANDBOOK  OF  MINING  DETAILS 


The  old  and  still  much  used  method  of  spitting  by  use  of  candles  or  miners' 
lamps  is  slow,  inefficient  for  a  large  number  of  holes,  and  dangerous.  Spitting 
one  fuse  by  candle,  the  second  fuse  from  the  first,  the  third  from  the  second, 
etc.,  is  good  but  can  be  used  only  when  the  holes  are  close  together.  The  advan- 
tage of  this  method  is  that,  when  through  spitting,  the  miner  is  certain  that  all 
the  fuse  was  spit  properly.  A  more  common,  and  far  better,  scheme  is  to  use 
an  extra  piece  of  fuse  about  18  in.  long,  which  is  slit  or  notched  along  one  side, 
the  notches  being  about  i  in.  apart.  When  ready,  light  one  end  of  this  fuse,  and 
as  the  fire  travels  along  the  fuse  it  will  spit  out  at  each  notch  in  succession.  As 
the  fire  spits  from  the  first  notch,  ignite  the  first  fuse,  with  the  second  notch  the 
second  fuse,  etc.,  the  advantages  being  that  there  is  the  same  interval  between 
the  lighting  of  each  fuse  and  the  method  is  rapid,  safe  and  easy. 

Table  for  Cutting  Fuse. — The  accompanying  drawing,  Fig.  8,  shows  the 
design  of  a  table  for  conveniently  cutting  fuse.  It  is  used  at  the  Blackberry  and 


FIG.    8. — FUSE   TABLE  AND    CAP   CRIMPER   USED    IN   JOPLIN   DISTRICT. 

Montana  mines,  near  Joplin,  Mo.  The  coil  of  fuse  is  carried  on  a  conical  spin- 
dle at  the  end  of  the  table,  and  from  this  spindle  the  fuse  is  unwound  as  it  is 
measured.  The  fuse  is  held  between  a  series  of  two  6o-d.  nails  driven  into  two 
cleats  of  iX2-in.  wood  that  are  screwed  to  the  table.  The  cutting  is  done  6 
in.  ahead  of  the  first  pair  of  nails,  so  that  there  are  no  long,  loose  ends  in  the 
way.  On  the  table  are  marks  which  are  used  in  measuring  the  several  lengths 
of  fuse  usually  required. 

In  cutting  the  fuse,  the  loose  end  from  the  coil  is  run  through  the  first  pair  of 
nails,  taken  around  the  turning  nails,  passed  through  the  last  pair  of  nails  that 
hold  the  loose  end  when  the  fuse  is  being  cut,  and  the  end  is  pulled  along  to  the 
mark  indicating  the  length  desired.  Then  with  the  fuse  cutters  the  fuse  is  cut 
off  at  the  other  end,  and  another  piece  of  fuse  measured  until  all  the  fuses  have 
been  cut,  the  different  pieces  being  left  securely  held  between  the  nails  until  the 
miner  is  ready  to  cap  them.  To  aid  in  the  cutting,  the  fuse  cutters,  which  are 
ordinary  crimpers,  are  made  with  a  spring  riveted  to  one  of  the  handles,  so  as  to 


EXPLOSIVES  29 

keep  the  jaws  apart.     This  increases  the  speed  of  cutting  the  fuse  somewhat,  and 
makes  the  use  of  the  crimpers  more  convenient. 

Blasting  in  Wet  Shafts  (By  E.  M.  Weston).— It  frequently  happens,  espe- 
cially when  shaft  sinking  with  machines  is  in  progress  in  wet  shafts,  that  the 
pumps  have  to  be  withdrawn  before  blasting.  This  may  mean  that  the  water 
has  risen  to  a  height  of  several  feet  above  the  bottom  of  the  shaft  before  the  holes 
can  be  fired. 

If  fuses  are  used  they  should  be  well  greased  just  where  the  detonator  has 
been  placed  on  one  end  and  inserted  in  the  primer.  It  is  true  economy  to  use 
two  fuses  and  two  detonators  in  the  leading  or  cut  holes  of  the  round  thereby 
lessening  any  risk  of  the  whole  round  being  hung  up  by  misfires.  All  fuses 
should  be  of  the  same  length,  from  6  to  12  ft.,  depending  upon  the  number  of 
holes  to  be  fired.  In  large  shafts  on  the  Rand  i2-ft.  fuses  are  used.  As  soon  as 
the  holes  are  charged  the  ends  of  the  fuses  are  tied  to  a  small  plank  or  a  wedge 
that  has  been  used  to  rig  the  base  for  the  machines,  6  in.  or  more  of  the  end  of 
the  fuses  projecting  above  the  plank  and  as  the  water  rises  all  fuse  ends  float. 

The  miners  work  in  pairs  lighting  the  fuses  from  the  back  of  the  shaft 
toward  the  bucket  or  skip  in  the  center.  "  Cheesa  sticks,"  as  they  are  called 
locally  are  made  by  splitting  blasting  gelatine  and  wrapping  it  around  pine 
sticks  about  18  in.  long.  In  a  wet  shaft  the  fumes  given  off,  though  poisonous, 
are  rapidly  absorbed  by  the  water  and  the  use  of  such  sticks  in  shaft  sinking  is 
justified.  One  miner  carries  the  lighted  stick  and  the  other  cuts  each  of  the 
back  rows  of  fuses  about  i  in.  from  its  end  and  rapidly  bends  it  back,  while  the 
other  miner  applies  the  stick  before  the  composition  becomes  damp.  When 
the  fuse  is  seen  to  spit  the  next  one  of  the  row  is  lighted.  If  the  fuse  does  not 
take  fire  after  the  first  cut  has  been  made,  another  cut  is  made,  and  no  fuse  is 
left  until  it  is  seen  to  spit.  The  next  rows  are  dealt  with  in  the  same  way, 
except  that  the  fuses  are  cut  several  inches  further  down  so  that  each  row  nearer 
the  center  of  shaft  will  explode  before  those  first  lighted. 

If  considered  more  convenient  the  reverse  order  of  lighting  may  be  adopted, 
but  the  advantage  of  lighting  the  back  rows  first  is  that  the  men  are  near  the 
bucket  when  all  the  fuses  have  been  lighted;  they  are  not  obliged  to  walk  over 
lighted  fuses  to  reach  the  bucket.  In  this  way  fuses  can  be  lighted  with  cer- 
tainty even  in  the  wettest  shafts  and  it  is  worth  while  at  mines  where  lower-grade 
explosives  are  used  to  have  some  blasting  gelatine  on  hand  with  which  to  make 
these  lighting  sticks,  as  gelignite  and  dynamite  are  too  granular  and  brittle  for 
the  purpose.  Substitutes  for  "cheesa  sticks"  made  of  chemical  combinations 
and  designed  to  give  off  no  carbon  monoxide  or  nitrous  oxide  are  being  intro- 
duced with  more  or  less  success  for  general  mine  work  on  the  Rand.  I  have  not 
however,  heard  that  they  have  been  used  successfully  in  wet-shaft  sinking. 

Blasting  in  Wet  Ground.  Where  a  blast  is  to  be  fired  in  wet  ground,  soap 
or  tallow  should  be  smeared  over  the  safety  fuse  at  the  place  where  it  enters 
the  blasting  cap  in  order  to  keep  the  charge  in  the  latter  perfectly  dry.  Oil 


30  HANDBOOK  OF  MINING  DETAILS 

or  grease  should  never  be  used  for  this  purpose  as  they  are  likely  to  soak  into  the 
fuse  and  destroy  the  efficiency  of  the  powder  which  it  contains. 

The  Calumet  System  of  Lighting  Fuse — There  are  many  different  ways  of 
lighting  blasting  fuse,  but  one  of  the  best,  when  there  are  not  too  many  to  be 
lighted,  is  the  method  used  in  mines  of  the  Calumet  &  Hecla  company  at 
Lake  Superior.  This  method  consists  in  taking  the  end  of  the  fuse 
sticking  out  of  the  hole  and  plastering  it  to  the  wall  with  a  piece  of  moist 
clay,  a  spot  being  chosen  so  that  in  case  there  is  a  draft  the  candle  used  to 
light  the  fuse  will  be  sheltered  from  the  air  current.  A  snuff  of  a  candle  about 
an  inch  long  and  having  a  wick  about  1/2  in.  in  length  is  then  placed  in  the 
clay  so  that  the  flame  will  reach  the  fuse.  The  candle  snuff  is  then  lighted  and 
allowed  to  burn  for  about  1/2  minute,  or  long  enough  for  the  tar  in  the  fuse 
covering  to  begin  to  bubble  out.  The  candle  is  then  blown  out  and  the  fuse 
to  the  next  hole  is  prepared  in  a  similar  manner.  This  fuse  is  heated,  the  candle 
in  turn  is  put  out  and  the  procedure  is  repeated  until  all  the  fuses  are  ready. 
Then  the  miner  relights  the  snuffs  and  hurries  away.  As  it  takes  a  minute  or 
so  for  the  candle  snuffs  to  burn  through  the  fuse  far  enough  to  reach  the  powder 
train,  the  miner  has  ample  time  to -get  to  safety,  while  there  can  be  no  failure  of 
the  fuse  to  light  and  there  is  no  necessity  for  the  miner  to  linger  at  the  breast  or 
face  after  the  holes  are  spr",  as  sometimes  a  miner  must  do  when  the  powder  has 
become  dislodged  from  a  split  fuse,  and  it  becomes  necessary  to  cut  it  again. 
Many  miners  lose  their  lives  by  lingering  in  just  this  mariner.  The  fuses  can 
be  cut  so  that  the  holes  will  explode  in  any  order  desired,  just  as  when  the  fuse 
is  lighted  in  some  other  manner.  The  time  required  for  the  flame  to  burn 
through  the  wrapping  seldom  varies  enough  to  cause  the  holes  to  explode  out 
of  the  order  desired.  There  is  a  limit  to  the  number  of  holes  that  can  be  fired 
by  one  man  in  this  way.  It  is  perfectly  safe  for  a  man  to  light  as  many  as  10 
fuses  in  this  manner,  but  as  there  is  a  certain  time  consumed  in  relighting  the 
snuffs,  it  is  debatable  whether  it  is  not  safer  to  use  some  other  method  when 
more  than  that  number  of  holes  has  to  be  fired  by  one  man. 

The  method  is  good  for  firing  shots  in  wet  ground,  provided  that  the  snuffs 
can  be  protected  from  the  drip  of  the  water.  When  that  cannot  be  done  the 
same  principle  of  firing — burning  through  the  covering  to  light  the  powder 
train  in  the  fuse — can  be  utilized  by  putting  the  fuses,  several  in  a  bunch,  on 
piles  of  oily  waste  and  lighting  the  waste. 

However,  when  spitting  his  shots  in  the  ordinary  manner,  a  miner  has  had 
to  recut  the  fuses,  he. should  never,  as  a  last  resort,  hold  the  fuse  in  the  flame 
of  his  light  in  the  hope  that  by  setting  fire  to  the  end  of  the  fuse  he  can  avoid  a 
misfire,  for  if  he  has  to  run  before  the  powder  train  catches,  the  covering  may 
smolder  for  many  minutes  before  the  powder  is  reached.  The  miner,  thinking 
that  the  fuse  did  not  ignite,  returns  to  the  face.  In  this  way  many  men  are  in- 
jured in  blasting.  The  snuff  method  of  firing  the  holes  avoids  all  such  dangers, 
as  the  flame  of  the  snuff  soon  burns  through  the  covering  to  the  powder.  The 


EXPLOSIVES 


important  point  in  the  Calumet  system  of  firing  is  that  there  can  be  nothing 
that  will  cause  the  miner  to  linger  at  the  face  after  once  he  has  started  to 
light  his  shots. 

Prevention  of  Drilling  into  Misfired  Holes  (By  John  T.  Fuller).— A 
common  cause  of  accident  in  shaft  sinking  is  drilling  into  a  misfired  hole  or 
striking  a  pick  into  a  misfire  while  mucking.  Such  accidents  are  due  frequently 
to  lack  of  information  as  to  the  exact  situation  of  the  holes  of  the  blasted  round. 
There  are  several  ways  of  lessening  the  danger.  One  is  to  have  each  shift 
charge  and  blast  the  holes  drilled  by  the  preceding  shift.  This  second  shift 
then  mucks  out  and  drills  the  holes  for  the  next  shift  to  blast.  A  second  way 
is  to  have  each  shift  drill,  blast  and  muck  its  own  round,  leaving  the  shaft  clean 


j-- 

End  View 


Side  View 
FIG.   9. — CLAY-FELLED   BOX  WITH  NAILS,   SHOWING   POSITION   OF  DRILL  HOLES. 

for  the  next  shift.  Both  of  these  methods,  however,  involve  more  or  less  of  an 
upset  of  the  usual  order  of  doing  things.  The  usual  order  is  to  have  the  shift 
coming  on  muck  the  rock  broken  by  the  preceding  shift,  then  drill  and  blast  a 
round  of  holes,  leaving  the  muck  in  turn  for  the  succeeding  shift. 

In  a  large  shaft,  sunk  under  my  direction,  the  device  herein  described  was 
used  to  aid  in  locating  the  holes  drilled  by  the  previous  shift.  A  box  was  made 
of  the  same  shape  as  the  shaft  and  built  to  a  convenient  scale,  as  shown  in  Fig.  9. 
It  was  about  4  in.  deep,  and  along  the  edges  saw  cuts  about  i  in.  deep  were  made, 


32  HANDBOOK  OF  MINING  DETAILS 

the  distance  between  each  representing  i  ft.  of  length  or  width  of  shaft.  A 
substantial  cover  with  hooks  to  fasten  it  securely  shut  was  also  provided.  This 
box  was  filled  with  moist  clay,  leveled  off  even  with  the  edges  and  lines  scribed 
across  the  surface  of  the  clay  by  a  pocket  knife  and  a  straight-edge,  using  the 
saw  cuts  as  guides.  The  box  of  clay  thus  represented  the  shaft  bottom,  sub- 
divided into  i -ft.  squares.  When  the  miner  went  down  to  charge  the  holes  he 
carried  this  box  with  him;  also  a  pocketful  of  2o-d.  wire  nails.  Before  charging 
a  hole,  he  would  thrust  his  tamping  stick  to  the  bottom,  which  enabled  him  to 
gage  the  direction  of  the  hole.  He  would  then  thrust  a  wire  nail  into  his  clay 
model  as  closely  as  possible  to  the  direction  and  position  of  the  hole  in  the  shaft 
bottom.  The  squares  greatly  aided  properly  locating  the  holes  in  the  model. 
Thus,  when  the  miner  had  completed  charging  and  had  lighted  the  round,  he 
returned  to  the  surface  with  an  almost  exact  reproduction  of  the  layout  of  holes. 

The  box,  with  its  record,  was  turned  over  to  the  miner  in  charge  of  the  suc- 
ceeding shift,  with  such  other  information  as  could  be  gathered  from  listening 
for,  and  counting  the  reports,  etc.  When  the  men  went  down  to  muck  out  after 
the  smoke  had  cleared,  they  took  the  box  with  them,  using  it  as  a  guide  in 
directing  the  mucking  and  in  locating  any  possible  misfires  after  the  shaft  had 
been  cleaned  out  and  before  work  was  started  on  the  new  round  of  holes.  It 
was  then  a  simple  matter  to  withdraw  the  nails,  smooth  over  the  clay  and  pre- 
pare the  box  for  the  next  record.  Not  a  single  accident  due  to  drilling  or 
mucking  into  misfired  holes  occurred  in  this  shaft,  although  it  was  about 
30X8  ft.  and  was  sunk  to  the  looo-ft.  level. 

Cartridges  for  Tamping. — The  importance  of  tamping  dynamite  in  drill 
holes,  especially  the  lower  grades,  is  rapidly  becoming  recognized  in  the  mining 
practice  of  the  United  States.  In  many  instances  the  powder  companies  furnish 
paper  cartridges  at  small  cost  for  incasing  the  tamping,  and  in  some  mines 
such  casings  are  used.  This,  however,  is  not  common  practice.  The  general 
practice  is  to  use  fine  material  from  the  vein  for  tamping.  This  is  far  better 
than  using  no  tamping  at  all,  but  the  sharp  pieces  of  rock  that  such  material 
usually  contains  are  likely  to  cut  the  fuse.  In  the  copper  mines  of  Lake  Supe- 
rior, the  miners  engaged  in  drilling  and  breaking  work  by  contract,  and  pay 
for  the  powder  they  use.  They  have  an  excellent  method  of  making  tamping 
cartridges.  The  tamping  is  clay  sent  down  from  the  surface  that  is  moist- 
ened and  mixed  with  fines  from  the  lode,  so  that  the  mass  is  coherent  when 
tightly  packed. 

The  casing  is  made  from  ordinary  newspaper,  according  to  two  methods,  in 
one  of  which  the  newspaper  is  sealed  with  candle  grease,  while  in  the  other  no 
sealing  is  used.  By  either  method  a  good  cartridge  is  obtained,  but  the  better 
method  is  that  in  which  the  paper  of  the  casing  is  sealed  with  candle  grease.  In 
both  methods  the  newspaper,  in  single  thicknesses,  is  wrapped  tightly  around  a 
piece  of  old  shovel-handle.  When  candle  grease  is  used,  the  paper  of  the  car- 
tridge ends  in  a  straight  line  running  lengthwise  with  the  piece  of  shovel-handle, 


EXPLOSIVES 


33 


about  which  it  has  been  wrapped  five  or  six  times.  The  outside  edge  of  the 
paper  is  sealed  by  dropping  candle  grease  on  it  and  pressing  the  paper  together 
while  the  grease  is  hot.  About  i  or  i  i  /  2  in.  of  paper  extends  below  the  piece 
of  shovel-handle.  This  is  folded  up  and  sealed  back  on  itself  by  hammering  it 
on  a  piece  of  wood  after  some  candle  grease  has  been  dropped  on  it.  The 
shovel  handle  is  then  removed,  the  cartridge  filled  with  tamping,  and  the  other 
end  sealed  in  a  similar  way  after  the  tamping  has  been  compacted  by  tapping 
the  bottom  end  of  the  cartridge  lightly  on  a  board.  Fig.  10  shows  the  method 
of  making  the  cartridge.  In  the  other  system  no  candle  grease  or  other  sealing 


Square  Roll  Bias  Roll  Folding  in  Th«» 

(Candle Grease Seal)  (NoSealing  Required)        Ends 

FIG.    10. — METHOD    OF   MAKING   TAMPING   CARTRIDGES. 


substance  is  used.  The  cartridge  is  not  so  strong;  yet  is  plenty  good  enough  for 
the  purpose.  More  paper  has  to  be  used,  as  the  piece  of  newspaper  is  wrapped 
about  the  shovel -handle  8  or  10  times.  The  lower  end  of  the  cartridge  is  sealed 
by  folding  the  paper  back  upon  itself  and  hammering  it  vigorously  on  a  piece  of 
board  so  as  to  mat  it  together.  The  seal  is  not  good,  but  the  cartridge  can  be 
removed,  tamping  put  into  it  and  compacted  by  tapping  the  bottom  on  a  board. 
Then  the  top  end  is  sealed  by  folding  it  in  several  times  on  itself  and  compact- 
ing the  paper  of  the  end  by  pounding  it  against  a  board.  Such  cartridges  are 
strong  enough  to  stand  any  ordinary  usage  in  loading  holes. 

Another  device  is  illustrated  in  Fig.  1 1.     It  is  made  by  threading  one  end  of  a 

9-in.  piece  of  brass  tubing  of  suitable  diameter.     The  bore  of  the  tube  is  fitted 

with  a  plunger  tapped  to  take  a  lo-in.  rod  about  1/4  in.  diameter.     The  other 

end  of  the  rod  is  threaded  and  attached  to  a  handle  by  two  flat  nuts  as  shown. 

3 


34  HANDBOOK  OF  MINING  DETAILS 

The  threaded  end  of  the  brass  tube  is  closed  by  a  cap  through  which  the  plunger 
rod  passes  as  shown  in  the  sketch.  A  hole  1/4  in.  diameter  is  drilled  in  the  side 
of  the  brass  tube  i  in.  below  the  cap.  This  tube,  a  small  planed  board,  a  few 
newspapers,  and  a  batch  of  moist,  fine  dirt  are  all  that  is  required  to  make  neat 
cartridges  that  will  give  no  trouble  in  tamping  a  drill  hole.  The  newspapers 
are  cut  into  strips  10  in.  wide  by  8  in.  long.  The  plunger  of  the  molding  tube 
is  withdrawn  to  the  cap  end  and  the  bore  is  packed  with  moist  dirt,  the 
i/4-in.  hole  at  the  cap  end  permitting  the  air  to  escape.  When  the  bore  has 
been  filled  the  tube  is  stood  upright  upon  the  planed  board  and  the  plunger  is 
pressed  down  to  compact  the  dirt  into  a  cylinder;  the  tube  is  then  laid  upon  its 
side  and  the  cylinder  removed  from  the  tube  by  pushing  on  the  plunger  handle, 
so  that  the  ejected  cylinder  of  dirt  lies  upon  a  piece  of  the  newspaper  laid  smoothly 
upon  the  planed  board.  To  complete  the  cartridge  it  is  only  necessary  to  roll 
it  up  in  the  paper  and  fold  over  the  ends.  These  tamping  cartridges  should  be 
carefully  placed  side  by  side  in  an  empty  powder  box  as  soon  as  made,  and 


FIG.    II. — DEVICE  POR  MOLDING  TAMPING  CARTRIDGES. 

when  needed,  the  box  of  cartridges  is  carried  to  the  place  where  blasting  is  to 
be  done.  As  all  the  cartridges  are  of  uniform  size  no  trouble  will  be  experi- 
enced in  placing  them  in  the  drill  holes  if  the  tube  is  of  the  proper  diameter  for 
the  size  of  hole  in  which  the  cartridges  are  to  be  used. 

In  the  diamond  mines  at  Kimberley,  South  Africa,  according  to  John  T.  Fuller, 
tamping  cartridges  are  made  by  native  boys  delegated  for  this  purpose.  The 
cartridges  are  made  of  cylinders  of  mud  covered  with  the  paraffin  paper  in  which 
the  bundles  of  dynamite  sticks  are  originally  wrapped. 

Use  of  High  Explosives. — At  a  great  many  mines  and  quarries  a  prejudice 
exists  among  the  miners  against  the  use  of  dynamite  of  a  higher  grade  than 
40%,  this  regardless  of  the  hardness  of  the  rock  mined.  In  mining  a 
moderately  hard  and  easily  fractured  material  40%  explosive  gives  good 
results,  and  has  the  advantage  of  being  comparatively  safe.  However,  even 
40%  dynamite  is  not  a  substance  with  which  anybody  can  afford  to  be 
careless.  If  a  man  is  careful  and  uses  ordinary  intelligence  in  handling  dyna- 
mite, 60,  80,  or  even  95  %  blasting  gelatin  can  be  handled  with  a  reasonable 
degree  of  security.  In  many  of  the  mines  of  the  West  where  ore  with  a 
hard,  tough  quartz  gangue  is  encountered,  60  and  even  80  %  dynamite  has 


EXPLOSIVES  35 

proved  far  more  satisfactory  than  the  lower  grade  material,  giving  a  broken 
product  which  can  be  easily  shoveled  in  the  cars  without  previous  cobbing  or 
popping.  In  several  instances,  nitroglycerin  and  even  guncotton  have  been 
used  with  success. 

The  pyrrhotite  ore  encountered  in  the  mines  of  the  Tennessee  Copper  Co.  is 
extremely  hard  and  tough  in  many  places.  In  the  Eureka  open-cut  mine,  where 
the  ore  is  very  tough  and  cemented  with  a  blue  quartz  gangue,  the  company 
is  experimenting  with  95%  blasting  gelatin  manufactured  by  the  Du  Pont 
Powder  Co.  As  far  as  can  be  seen  from  the  work  already  done,  this  explosive 
is  giving  excellent  results.  Owing  to  the  prejudice  of  the  miners  against  high 
explosives,  it  was  introduced  at  first  without  telling  the  miners  of  its  grade.  Now, 
however,  after  the  men  have  become  accustomed  to  using  it,  they  feel  no  more 
fear  of  it,  seemingly,  than  they  do  of  the  ordinary  40  or  60%  grade  dyna- 
mite. It  has  been  found  to  shatter  the  rock  much  more  than  a  lower  grade  pow- 
der, and  about  eight  or  nine  sticks  of  the  gelatin  will  do  as  much  work  or  break 
down  as  much  rock  as  nearly  double  that  many  sticks  of  40  %  dynamite. 

In  the  underground  workings,  objection  is  made  to  the  use  of  gelatin  even 
where  the  men  are  not  afraid  of  it,  as  they  find  it  will  not  stay  in  upcast  holes. 
In  tamping  it  acts  like  so  much  rubber  and  unless  some  paper  is  stuffed  in  the 
mouth  of  the  hole  it  is,  very  likely  to  roll  out,  this  of  course  being  a  source  of 
danger. 

The  decision  as  to  the  grade  of  dynamite  to  be  used  should  depend  upon  the 
results  obtained.  In  a  locality  where  labor  is  expensive,  it  may  be  more  eco- 
nomic to  use  high-grade  explosive  on  account  of  the  labor  saved  from  blocking 
or  sledging  the  ore  shot  down,  whereas,  with  similar  ore,  in  another  region  where 
cheap  labor  is  available  it  may  prove  cheaper  to  use  a  lower  grade  of  dynamite 
and  break  the  large  blocks  of  ore  by  hand.  Each  superintendent  must  deter- 
mine the  grade  of  explosive  best  adapted  to  his  conditions. 

Joplin  Scraper  and  Loading  Stick. — The  ore  in  the  Joplin  mines  is  a  min- 
eralization of  stratified  beds.  The  roof  is  good  and  in  stoping  a  system  of  drill- 
ing is  used,  in  which  a  bench  is  taken  up  by  a  series  of  flat  holes  after  the  ore 
next  the  roof  has  been  blasted  out  in  a  heading.  In  this  bench  work  some  of 
the  deepest  drilling  in  underground  metal  mining  in  the  United  States  is  done. 
Holes  1 8  ft.  deep  are  not  uncommon,  i6-ft.  holes  are  common,  and  12-  and  14- 
ft.  holes  are  typical  practice  in  the  bench  portion,  which  is  called  the  stope. 

To  break  the  heavy  burdens,  it  is  necessary  to  chamber  the  bottom  of  the 
flat  holes,  and  because  of  the  rapid  wearing  of  the  bits,  it  is  often  necessary 
to  blast  the  hole  for  gage,  so  that  one  bit  may  follow  another.  This  springing 
of  the  hole  is  called  "squibbing."  The  squibbing  makes  the  bore  of  the  hole 
ragged,  therefore  difficult  to  load.  This  and  the  occurrence  of  cavities  in  the 
ore,  through  which  some  of  the  holes  pass,  makes  "railroading"  of  the  powder 
to  the  bottom  of  the  hole  ahead  of  the  loading  stick  impossible.  A  pointed 
tamping  stick  is  therefore  used.  Some  sticks  are  pointed  with  a  piece  of  copper 


HANDBOOK  OF  MINING  DETAILS 


wire;  others  with  a  copper  nail.  The  ground  is  flinty,  so  that  the  use  of  a  steel 
wire  nail  in  the  tamping  stick  would  almost  surely  be  attended  by  sparking.  A 
copper  nail  is  sometimes  used,  but  this  is  not  considered  good  practice  by  the 
powder  companies.  The  best  practice  is  to  use  a  tamping  stick  with  a  wooden 
point.  In  some  of  the  sticks  a  point  is  made  by  sharpening  the  tamping  stick 
itself,  but  it  is  preferable  to  insert  a  round  piece  of  hardwood  in  an  auger  hole  in 
the  end  of  the  stick  and  to  sharpen  this  inserted  piece  of  wood.  The  stick  of 
powder  is  impaled  on  the  point,  so  that  it  can  be  made  to  pass  any  irregularities 
in  the  bore  and  deposited  at  the  bottom  of  the  hole.  This  is  important,  especially 
in  squibbing,  as  part  of  the  hole  may  be  lost  if  the  squibbing- dynamite  is  not 
at  the  bottom  of  the  hole  when  fired.  The  other  end  of  the  stick  is  used  in 
tamping. 


WooctPin  - 


FIG.    12. — SCRAPER  AND    LOADING   TOOL   USED  AT   JOPLIN. 

On  account  of  the  crumbling  of  the  ore,  scraping  out  the  deep  holes  is  a 
difficult  operation,  and  it  is,  therefore,  important  that  the  machine  man  be  able 
to  keep  the  spoon  of  the  scraper  in  its  proper  position  in  respect  to  the  bottom 
of  the  hole.  Instead  of  using  round  iron  for  making  the  scraper,  a  piece  of 
3/8Xi/2-in.  steel  is  used  for  the  shorter,  and  5/8Xi/2-in.  for  the  longer 
scrapers.  The  spoon  is  made  about  5  in.  long,  with  a  nose  nearly  the  diameter 
of  the  steel  used  in  the  hole.  When  the  wide  side  of  the  scraper  rod  is  horizon- 
tal, the  nose  of  the  scraper  is  turned  either  up  or  down  in  the  hole.  It  is, 
therefore,  possible  to  pull  the  scraper  with  its  load  out  of  a  hole,  while  with  a 
round  handle,  it  is  not  uncommon  to  lose  the  load.  The  advantage  of  a  handle 


EXPLOSIVES  37 

of  rectangular  section  is  evident.  Drawings  of  the  scraper  and  loading  tool  used 
at  Joplin  are  shown  in  Fig.  12. 

Breaking  Ground  for  Steam  Shovels.— Two  systems  of  blasting  the  ground 
to  be  excavated  by  steam  shovels  are  used  in  the  Mesabi  district,  Minn.  The 
overburden  to  be  blasted  is  glacial  drift,  while  the  ore  is  soft  hematite.  Where 
the  bench  to  be  broken  does  not  exceed  20  or  25  ft.  in  height,  the  usual  method 
is  to  drill  holes  15  to  18  ft.  from  the  edge  and  about  15  ft.  apart,  extending  along 
the  entire  bench  to  be  broken.  A  handle  bar  is  fastened  to  the  drill  steel  and 
two  men  operate  the  drill  by  means  of  this  handle.  The  drill  is  lifted  about  2  ft. 
and  dropped  by  its  own  weight.  The  men  walk  around  in  a  circle  3  ft.  in  diam- 
eter and  in  this  way  turn  the  drill.  When  the  hole  is  the  required  depth  (about 
20  ft.)  one  or  two  sticks  of  7/8-in.  powder  are  lowered  and  discharged  to  spring 
the  hole.  The  hole  is  again  opened  and  5  to  15  sticks  of  dynamite  are  placed  in 
the  bottom  of  the  hole  and  discharged  to  spring  the  hole  further,  so  that  it  will 
contain  10  to  15  kegs  of  black  powder.  When  loading  the  hole  with  black 
powder,  a  stick  of  dynamite,  in  which  two  caps  and  fuses  are  inserted,  or  an 
electric  fuse  attached,  is  lowered  in  the  hole  and  powder  is  filled  around  it. 
After  the  powder  is  in  place,  the  hole  is  firmly  tamped  with  sand.  Each  hole  is 
discharged  separately.  During  cold  winter  weather  only  one  hole  is  discharged 
at  a  time,  and  the  loosened  material  is  moved  before  it  has  an  opportunity  to 
freeze.  In  the  summer  often  15  or  20  holes  will  be  fired,  one  after  the  other, 
yielding  enough  loose  material  to  last  the  steam  shovel  several  days. 

The  other  system  of  loading,  called  "gophering,"  is  used  when  the  ground  is 
so  dry  or  sandy  that  the  vertical  hole  cannot  be  kept  open,  or  when  the  bench  is 
too  high  to  drill  from  the  top.  In  this  method  holes  are  drilled  in  from  the  side. 
The  total  depth  is  20  to  25  ft.  A  pointed  i  i/4-in.  drill  bar  is  used.  After  it 
has  been  driven  a  few  feet  with  hammers,  the  bar  is  withdrawn,  and  sticks  of 
7/8-in.  dynamite  are  placed  end  to  end  in  the  hole  and  discharged.  This 
loosens  the  ground  and  the  dirt  is  then  taken  out  by  means  of  a  long-handled 
shovel.  In  this  way  a  hole  10  or  12  in.  in  diameter  is  opened.  The  hole  is 
inclined  at  an  angle  of  15  to  20°.  The  lower  end  of  the  hole  is  sprung  with  8  or 
10  sticks  of  7/8-in.  powder  and  cleaned  out.  Ten  to  15  kegs  of  black  powder 
are  then  used.  The  black  powder  is  fed  into  the  hole  by  means  of  a  box 
3  X3  X 15  in.,  nailed  to  a  22-ft.  pole.  Another  method  of  loading  is  by  means  of 
a  V-shaped  trough  made  of  3/4X4-in.  boards.  The  powder  is  poured  into  the 
upper  end,  and  the  trough  given  a  backward  and  forward  motion,  and  in  this 
way  the  powder  soon  finds  its  way  to  the  bottom  of  the  hole.  Two  men  can 
usually  put  in  two  of  these  holes  per  shift.  If  the  ground  is  loose  enough  to 
work  with  the  shovel,  it  is  not  necessary  to  spring  the  hole  before  the  bottom  is 
reached.  When  boulders  are  encountered,  they  are  broken  by  discharging 
dynamite  on  their  face.  In  the  case  of  a  boulder  too  large  to  break  in  this  way, 
it  is  often  necessary  to  start  another  hole. 

The  Necessity  for  Strong  Detonators. — In  detonating  high  explosives,  the 


38  HANDBOOK  OF  MINING  DETAILS 

stronger  or  sharper  the  initial  shock  the  quicker  and  more  thorough  is  the  detona- 
tion of  the  charge.  If  the  detonation  is  slow  and  incomplete  a  greater  quantity 
of  explosive  is  required  to  do  the  same  work,  and  large  volumes  of  poisonous  gas 
are  evolved— a  matter  of  serious  consequence  in  underground  work.  Quick 
and  complete  detonation  results  in  a  minimum  of  flame,  a  point  of  first  impor- 
tance with  those  explosives  intended  for  use  in  the  presence  of  inflammable  gas 
or  coal  dust.  Electric  fuses  or  blasting  caps  too  weak  to  detonate  a  charge  of 
high  explosives  frequently  generate  sufficient  heat  to  ignite  it.  The  effect  of  a 
detonator  on  a  charge  of  high  explosives  in  a  bore  hole  is  by  no  means  infinite,  but 
decreases  with  distance.  It  is,  therefore,  easy  to  understand  the  necessity  for 
using  detonators  sufficiently  strong  for  the  effect  of  the  detonator  to  extend  as  far 
as  possible  through  the  charge.  It  should  not,  however,  be  understood  that  the 
detonator  should  be  placed  in  the  center  of  the  charge,  for  numerous  tests  have 
shown  that  the  greatest  effect  of  a  detonator  is  straight  away  from  its  loaded  end, 
and  in  a  line  with  its  long  axis,  i.e.,  a  detonator  will  explode  a  cartridge  of  dyna- 
mite farther  away  from  it,  if  it  is  lying  with  the  loaded  end  pointed  toward  the 
cartridge,  than  it  will  if  it  is  lying  parallel  to  the  cartridge.  It  may  be  impossible 
to  explain  this,  but  it  is  known  to  be  a  fact.  In  deep  bore  holes  loaded  with  long 
charges,  it  is  well  to  place  caps  in  cartridges  of  explosives  at  intervals  of  at  least 
5  ft.  throughout  the  charge,  so  that  the  effect  of  the  explosive  material  which  they 
contain  will  extend  the  entire  length  of  the  charge. 

Priming  With  Electric  Fuse. — To  prime  a  high-explosive  cartridge  for 
electric  blasting  the  fuse  cap  should  be  inserted  into  the  center  of  one  end  of  the 
cartridge  and  pointed  directly  toward  the  opposite  end.  The  two  lead  wires 
should  then  be  brought  together  up  one  side  of  the  cartridge  and  tied  in  place 
with  string  at  points  an  inch  or  two  from  either  end  of  the  cartridge.  The 
common  practice  of  inserting  the  cap  diagonally  into  the  side  of  a  cartridge  and 
then  looping  the  wires  about  the  cartridge  in  several  half  hitches  is  to  be  con- 
demned. In  looping  the  wires,  the  insulation  is  likely  to  be  broken,  causing 
short  circuiting  or  leakage  of  current  in  wet  work;  the  wires  may  even  be  broken. 
The  common  practice,  when  the  cap  is  pointed  diagonally  toward  the  end  of  the 
cartridge,  is  to  place  the  cartridge  so  that  the  end  of  the  cap  will  be  nearest  the 
outside  or  top  of  the  charge.  Any  pull  on  the  lead  wires  tends  to  swing  the  cap 
in  a  position  more  at  right  angles  to  the  long  axis  of  the  cartridge.  Thus  the 
end  of  the  cap  may  easily  be  swung  entirely  out  of  the  explosive.  In  blasting, 
the  principal  part  of  the  detonating  charge  should  be  placed  in  the  center  of  the 
cartridge  of  explosive,  and  not  to  one  side  or  entirely  outside,  against  the  paper. 
A  great  many  missed  shots  are  doubtless  caused  by  improper  priming. 

Device  for  Clearing  a  Hung-up  Chute  (By  J.  Bowie  Wilson).— All  under- 
ground managers  have  at  some  time  been  worried  by  ore  chutes  choking  and 
hanging  up  out  of  reach  of  the  trammer's  bar.  When  the  material  consists  of 
fine  clayey  stuff  the  only  remedy  is  practically  to  dig  it  out.  If  the  material 
consists  of  rock,  even  if  it  contains  a  proportion  of  clay,  and  the  block  is  due  to 


EXPLOSIVES 


39 


the  large  pieces  keying  together  and  arching  over  in  the  chute,  the  following 
method  of  clearing  the  chute  will  be  found  better  and  certainly  safer  than  attempt- 
ing to  shoot  down  the  pass  by  tying  pieces  of  dynamite  to  a  tamping  stick.  This 
scheme  is  used  at  the  Mount  Morgan  mine  in  Queensland,  and  consists  in  firing 
a  wooden  plug  from  a  small  cannon  placed  in  the  bottom  of  the  chute.  The 
cannon  is  made  from  a  length  of  steel  shafting,  the  center  being  bored  out  in  a 
lathe  and  a  touch-hole  drilled  large  enough  to  take  the  ordinary  fuse  in  use  at 
the  mine.  The  end  of  the  shafting  is  turned  down  to  fit  into  a  hole  in  the  top 
of  a  short  length  of  9  Xp-in.  hardwood  timber  of  such  shape  that  when  the  device 
is  laid  on  the  floor  of  the  chute  and  resting  against  the  chute  door,  the  cannon 
will  point  up  the  center  of  the  raise.  Fig.  13  shows  the  construction  of  the 
cannon.  It  is  charged  with  ordinary  black  blasting  powder  and  a  plug  of  hard- 
wood timber  is  tapped  home  in  its  mouth.  A  fuse  is  then  inserted  into  the 


Wooden  Plug 


Floor  of 
Chute 


FIG.    13. — CANNON  FOR  OPENING  CHUTES. 


touch-hole  to  explode  the  powder.  In  action  the  cannon  is  a  big  popgun,  and 
on  the  powder  exploding,  the  wooden  plug  hits  the  keyed  material  with  a  good, 
sudden  blow.  If  the  shot  is  successful  the  material  falls  upon  the  gun  and  its 
carriage,  but  these,  being  of  a  simple  design,  are  in  no  way  hurt  and  can  be 
recovered.  A  knock  against  the  side  of  the  truck  suffices  to  clear  the  cannon 
of  anv  material  and  it  is  thrown  down  in  the  tunnel  beside  the  chute  until 
required  again.  If  the  chute  is  not  freed  by  the  first  shot  it  will  generally  be 
found  to  open  after  several.  A  great  advantage  of  this  method  is  that  the  men 
are  in  no  danger  when  using  it. 


40  HANDBOOK  OF  MINING  DETAILS 

STORAGE  OF  EXPLOSIVES 

Powder  Magazines. — The  mining  law  of  the  Transvaal  is  strict  with  respect 
to  the  construction  and  management  of  magazines  for  explosives.  Some  of  the 
provisions  are  the  following: 

Care  shall  be  taken  that  explosives  magazines  are  erected  only  at  such 
places  where  there  is  a  suitable  depth  of  soil  or  sand.  In  no  case  shall  an 
explosives  magazine  be  erected  upon  rocky  ground.  In  the  construction  and 
erection  of  the  magazines  only  the  lightest  and  most  suitable  material  avail- 
able shall  be  used  for  walls  and  roofs.  Solid  arched  roofs  are  particularly 
prohibited. 

The  magazine  shall  be  at  least  6  ft.  6  in.  in  the  clear  from  floor  to  ceiling,  and 
shall  comprise  at  least  two  compartments,  one  called  the  lobby,  which  is  acces- 
sible from  the  outside,  and  used  for  the  reception  and  delivery  of  explosives;  the 
other  called  the  storage  room,  which  is  accessible  only  from  the  lobby  and  is  used 
for  the  storage  of  explosives. 

The  outer  door  to  the  lobby  must  open  outward,  and  be  faced  with  sheet  iron 
about  1/4  in.  thick,  and  fitted  with  a  good  lock,  for  which  purpose  a  padlock  will 
not  be  deemed  to  be  sufficient. 

The  compartments  of  a  magazine  shall  be  properly  ventilated  by  cowled 
ventilators  in  the  roof,  or  properly  protected  ventilating  channels  in  the  gables. 
The  highest  temperature  allowed  in  the  storage  room  shall  not  exceed  95°  F. 

The  ceiling  of  a  magazine  shall  be  of  wood,  and  its  inner  sides  shall  be  wood- 
lined,  the  lining  to  be  at  least  3  in.  distant  from  the  walls  and  the  intervening 
space  filled  with  some  uninflammable  non-heat-conducting  material.  The  floor 
shall  be  of  wood,  of  sufficient  strength,  and  shall  be  well  ventilated  beneath;  it 
shall  also  be  provided  with  a  proper  drain  for  insuring  the  dryness  of  the  maga- 
zine. Roofs  of  galvanized  iron  shall  have  wood  lining  immediately  against 
the  iron.  All  nails,  fastenings,  locks,  keys  and  fittings  inside  the  magazine  shall 
be  made  of  wood,  brass  or  copper. 

The  magazine  shall  be  fitted  with  a  reliable  lightning  conductor,  supported 
on  a  vertical  post  standing  clear  of  the  building,  but  not  more  than  18  in.  from 
one  of  the  walls,  and  rising  at  least  6  ft.  above  the  highest  point  of  the  magazine. 
This  lightning  conductor  shall  be  carried  to  a  properly  laid  earth  plate. 

A  surface  or  sub-surface  magazine  shall  be  surrounded  by  an  outer  earth  wall, 
and  the  bottom  of  the  inner  slope  of  the  same  shall  not  be  less  than  3  ft.  from 
the  sides  of  the  building.  This  earth  wall  shall  have  a  natural  slope  on  either 
side,  and  be  3  ft.  wide  at  the  top,  and  as  high  as  the  highest  point  of  the  roof. 
The  approach  to  the  precincts  of  the  magazine,  through  the  outer  earth  wall, 
shall  have  a  strongly  built  gate,  which  shall  be  kept  locked.  The  entrance  to 
the  magazine  shall  be  either  in  a  broken  line,  or  the  door  shall  be  protected 
by  an  outer  protecting  earth  wall  entirely  shielding  the  entrance. 

A  reliable  self-registering  thermometer  shall  be  kept  in  the  storage  room  of 
every  explosives  magazine.  At  least  one  pair  of  magazine  shoes  shall  be  kept 


EXPLOSIVES 


in  the  lobby  of  every  magazine,  and  no  person  shall  enter  the  storage  room  of 
any  magazine  except  when  wearing  such  shoes  or  when  barefooted. 

Powder  House  with  Concrete  Roof  (By  Claude  T.  Rice). — A  powder 
house  with  a  concrete  roof,  such  as  is  used  by  the  Copper  Range  company's 
mines  in  Michigan,  is  shown  in  Fig.  14.  In  designing  the  roof  the  weight  of 
150  Ib.  per  cubic  foot  of  concrete  and  31  Ib.  pressure  per  square  foot  for  wind, 
snow  and  other  loads  were  taken,  and  the  ordinary  force  diagram  for  designing 


I" 

ll 

Ij 

i! 

it 

1 

-}**•* 

[Is 

9 

.IP 

;    y' 

r  '  i  « 

J     ^X  * 

i! 
ii 

2?^ 

/** 

r/ 

Detail  of  Arch  Centers 


FIG.    14. — POWDER  HOUSE  AT  THE   CHAMPION   MINE. 

arches  used  in  proportioning  the  thickness.  The  concrete  was  mixed  in  the 
proportions  i  :  2  :  4  to  i  :  3  :  5.  No  waterproofing  mixture  was  added,  but 
instead  the  whole  roof  was  covered  with  a  thin,  smooth  layer  of  i  :  i  cement. 
The  concrete  is  reinforced  with  rods  of  i/2-in.  iron  at  24-in.  centers.  The 
side  walls  are  of  masonry  built  of  waste  rock  from  the  mine,  and  are  tied  together 
at  the  top  crosswise  by  three  i-in.  rods.  A  small  ventilating  hole  is  left  in  the 
end  walls  near  the  top.  The  building  is  not  for  the  thawing  of  the  dynamite, 
but  merely  for  its  safe  storage  at  the  surface. 


42  HANDBOOK  OF  MINING  DETAILS 

Concrete  Powder  House.— At  the  properties  of  one  large  Eastern  mining 
company  the  powder  houses  are  about  6X12  ft.,  built  entirely  of  concrete. 
The  door  and  door  frame  are  wood,  but  covered  with  sheet  iron.  The  floor  is 
cemented.  These  houses  are  used  for  the  storage  of  only  a  few  boxes  of  powder 
for  immediate  use  at  the  mine.  There  are  a  number  of  these  buildings,  and 
each  shipment  of  powder  is  distributed  among  them.  This  avoids  the  storage 
of  large  quantities  at  one  place.  However,  the  design  of  these  magazines  is  not 
one  that  is  to  be  recommended. 

Powder  Storage  Underground. — At  the  Leonard  mine,  Chisholm,  Minn., 
only  one  box  of  powder  is  taken  underground  for  each  working  face.  This 
powder  is  kept  under  lock  and  key  in  a  box,  2  X2  X4  ft.  In  this  box  is  also  kept 
one  box  of  candles  and  whatever  fuse  and  caps  are  necessary  for  each  face. 
The  day  shift  and  the  night  shift  each  have  a  key  to  the  box.  These  boxes  are 
so  distributed  that  they  are  not  less  than  75  ft.  apart  and  at  a  safe  distance  from 
the  working  face.  This  distribution  of  powder  prevents  any  serious  explo- 
sions, such  as  may  occur  when  many  boxes  are  kept  in  one  magazine. 

[However,  it  is  not  good  practice  to  keep  caps  and  fuse  and  powder  in  the 
same  box. — EDITOR.] 

FROZEN  DYNAMITE 

The  nitroglycerin  in  dynamite  freezes  at  42  to  46°  F.,  and  when  frozen  is 
insensible  to  detonation  but  explodes  readily  by  friction  or  by  breaking  or  cut- 
ting the  cartridge.  It  should  be  thawed  by  putting  it  in  a  watertight  case  and 
immersing  in  warm  water,  or  by  laying  it  in  a  warm  room.  It  should  not  be 
thawed  by  putting  the  sticks  in  warm  water,  as  a  certain  amount  of  the' 
nitroglycerin  is  lost  through  its  coming  out  of  the  cartridge  and  sinking  to  the 
bottom.  This  water  may  perchance  be  heated  again,  in  which  case  the  collected 
nitroglycerin  is  likely  to  explode.  It  should  also  be  noted  that  in  case  any 
water  does  contain  nitroglycerin  mingled  with  it,  that  the  water  should  be  poured 
out  carefully  and  not  thrown  out  violently  on  the  ground.  It  is  also  dangerous 
to  hold  a  stick  of  frozen  dynamite  over  a  hot  object,  as  one  drop  of  the  nitro- 
glycerin may  ooze  out,  fall,  explode  and  set  off  the  stick.  It  is  hardly  necessary 
to  state  that  it  is  imprudent  to  thaw  dynamite  by  carrying  it  down  one's  boot  leg 
or  inside  one's  shirt.  There  are  only  two  safe  ways  and  those  are  the  ones  given 
above,  and  those  should  not  be  pursued  too  enthusiastically.  Make  haste 
slowly. 

Thawing  Dynamite.— A  dynamite  thawer,  described  by  R.  E.  Tilden,  of 
Winnemucca,  Nev.,  is  effective,  safe,  and  has  the  advantage  that  the  smallest 
mine  can  afford  one;  its  cost  is  nothing.  To  thaw  the  dynamite  use  a  large 
bottle,  fill  with  warm  water,  then  place  the  cartridges  around  the  bottle  in  layers, 
wrapping  them  in  place  with  a  woolen  rag  or  cloth,  tied  by  a  string.  The  size 
of  bottle  selected  should  be  governed  by  the  amount  of  powder  to  be  thawed  for 


EXPLOSIVES 


43 


use  in  one  place  in  the  mine  and  by  the  time  that  will  elapse,  after  being  taken 
underground,  until  the  powder  is  used.  The  bottles  may  be  conveniently  car- 
ried in  pails.  Powder  taken  into  the  mine  in  the  morning  will  be  thawed  and 
remain  so  until  evening. 

A  simple,  economical  and  perfectly  safe  method  of  thawing  dynamite  is  that 
which  has  been  used  for  over  a  year  at  the  Van  Roi  mine,  near  Silverton,  Slocan 
district,  B.  C.  Douglas  Lay,  superintendent  of  the  mine,  describes  this  as  being 
merely  an  adaptation  of  the  widely  known  principle  of  heating  by  hot-water 
coils.  The  thawing  house  is  a  building  occupying  a  floor  space  of  about  8  X 10  f  t. 
Placed  in  it  is  the  water-supply  tank — a  barrel — kept  full,  or  nearly  full,  of 
water,  which  is  heated  by  means  of  pipes  passing  to  a  coil  in  a  stove  in  another 
building  about  300  ft.  distant  from  the  thawing  house,  and  at  a  considerably 


FIG.    15. — THAWER  FOR  DYNAMITE. 

lower  level.  The  pipes  from  the  barrel,  which  connect  with  the  stove  coil,  are 
placed  in  a  box  buried  in  the  ground,  to  insure  insulation.  In  the  thawing 
house  there  is  a  box  5  ft.  long,  2  ft.  wide,  and  2  ft.  deep,  with  a  lid.  A  large  pipe 
coil,  connected  with  the  hot- water  column,  is  in  the  bottom  of  the  box;  it  is 
covered  with  sawdust,  and  the  sticks  of  dynamite  are  placed  in  the  box.  The 
sawdust  serves  to  absorb  any  exuded  nitroglycerin,  and  is  renewed  frequently. 
The  building  containing  the  heating  stove  and  coil  is  erected  near  the  entrance 
to  one  of  the  mine  adits  and  is  used  as  a  dry  room  by  the  miners.  As  already 


44 


HANDBOOK  OF  "MINING  DETAILS 


mentioned,  it  is  remote  from  the  thawing  house,  so  that  the  latter  would  be 
absolutely  safe,  even  if,  from  any  cause,  the  former  should  catch  fire. 

In  Fig.  15  is  shown  a  type  of  thawer  used  by  the  Oliver  Mining  Co.,  Hibbing, 
Mich.,  which  has  given  excellent  satisfaction.  It  is  made  of  galvanized  iron, 
about  10X10X16  in.  high.  Twelve  2  i/4-in.  tubes  are  soldered  in,  giving  the 
appearance  of  a  tubular  boiler.  Six  inches  from  the  bottom  is  a  water-tight 
partition,  above  which  is  water  to  cover  the  tubes.  The  ends  of  the  tubes  are 
open  for  the  insertion  of  the  sticks  of  dynamite.  Two  or  three  short  pieces  of 
candles  placed  below  furnish  heat  for  warming  the  water,  unless  hot  water  is 
available.  A  metal  cover  is  placed  over  the  box.  The  candles  are  thoroughly 
inclosed  beneath  and  obtain  an  ample  supply  of  air  through  three  ventilation 
holes  on  each  side. 

At  the  Traders'  mine,  Iron  Mountain,  Mich.,  a  small  house  has  been  con- 
structed in  which  to  thaw  all  the  powder  used  in  the  mine.  The  building  is 
10X12  ft,  built  of  12  Xi2-in.  timbers  placed  close  together  and  is  on  alow  piece 
of  ground  sheltered  by  a  high  bank.  Exhaust  steam  from  the  boiler  house  is 


FIG.    1 6. — THAWING   HOUSE   AT   TRADERS    MINE. 

used  for  heating  the  building.  It  enters  through  a  3-in.  pipe  above  the  tray 
upon  which  the  powder  is  placed,  and  then  passes  down  and  into  a  cylinder 
12  in.  in  diameter  and  5  ft.  long  which  is  beneath  the  tray.  Fig.  16  shows  the 
arrangement.  The  tray  itself  is  made  of  i/2-in.  iron  bars  placed  about  1/2  in. 
apart.  It  is  3  X6  ft.  and  affords  ample  room  for  four  or  five  boxes  of  powder. 
This  has  been  in  use  14  years.  Only  one  day's  supply  of  powder  is  kept  in  this 
building.  The  fuse  and  caps  are  in  another  building  50  ft.  away.  The  main 
powder  storage  house,  where  carload  shipments  are  kept,  is  1/4  mile  distant. 
Thawing  Dynamite  by  Electricity. — A  method  of  thawing  dynamite  used 
by  the  Vermont  Copper  Co.  consists  in  heating  the  thawing  box  by  electricity. 
The  box  referred  to  is  about  16X40X36  in.,  and  stands  on  edge.  It  is  made  of 
wood  with  a  number  of  trays  that  will  slide  in  and  out.  Each  tray  is  made  of 
small  strips  of  wood,  and  it  is  upon  these  trays  that  the  powder  is  placed.  Doors 
are  made  as  nearly  air-tight  as  possible.  The  lower  8  in.  of  the  box  has  wire 
coils  through  which  the  current  is  passed,  and  the  heat  from  the  coils  warms  the 


EXPLOSIVES  45 

box.  Above  the  coils  is  a  thin  sheet  of  galvanized  iron,  to  prevent  any  powder 
or  nitroglycerin  from  coming  in  contact  with  them.  The  sheet  iron  is  covered 
with  asbestos  sheet.  The  box  is  usually  thoroughly  heated  before  placing  the 
dynamite  on  the  trays,  and  then  the  current  is  turned  off.  The  thawer  is  placed 
in  some  remote  part  of  the  mine,  at  the  end  of  a  drift  which  can  be  closed 
from  draft,  and  is  thoroughly  inclosed  in  a  small  house. 


Ill 

ROCK  DRILLS 

Bits  and  Drill  Parts — Pointers  on  Operation — Economics  of  Practice. 

BITS  AND  DRILL  PARTS 

Air-hammer  Drilling  in  Sticky  Ground  (By  George  E.  Addy). — The 
sticking  of  a  drill  steel  in  soft,  clayey  ground  may  be  overcome  by  welding  a  piece 
of  ribbed  drill  steel,  A  in  Fig.  17,  to  a  bull  pick  B.  The  drill  so  made  can  be 
driven  with  a  hammer  drill.  If  a  set  of  three  drills  is  made,  the  shorter  steels 
having  the  larger  points,  a  hole  3  ft.  deep  can  be  drilled.  These  pick-pointed 
drills  will  be  found  to  be  time  savers  as  compared  with  the  usual  types  of  drills, 
or  with  driving  a  bull  pick  with  a  hammer. 


FIG.   17. — A   PICK-POINTED   DRILL  FOR   SOFT  GROUND. 

A  Drill  for  Soft  Ground. — The  vanadium  deposits  of  San  Miguel  county, 
Colo.,  occur  in  sandstone  which  is  generally  soft  and  often  moist.  It  is  difficult 
to  drill  this  sandstone  because  the  moist  sand  sticks  in  the  holes.  To  obviate 
this  the  miners  use  a  hand  drill  made  of  steel  tubing,  in  which  saw  teeth  are  cut 
on  the  end,  set  out  for  clearance  as  shown  in  Fig.  18.  With  this  drill,  upper 
holes  are  regularly  drilled,  the  cuttings  coming  out  of  the  bit  through  the  hollow 
center.  The  device  is  satisfactory  within  the  limits  for  drilling  shallow  holes  in 
soft  wet  ground. 


FIG.    l8. — DRILL  MADE   OF   STEEL  TUBING. 

Design  of  Drill  Bits  (By  Ward  Blackburn).— The  efficiency  of  a  rock- 
drilling  plant  is  determined  by  the  amount  of  power  delivered  to  the  bit  and 
converted  into  cutting  power.  No  matter  how  efficient  the  compressing  plant 
and  the  rock  drills,  or  how  careful  the  drill  operator,  if  the  bit  is  dull  or  of 
incorrect  shape,  the  rock  is  not  cut,  good  energy  is  wasted,  and  money  and  time 
are  lost,  in  reaming  the  bore  hole  or  in  pulverizing  the  rock,  and  the  real  object 
of  the  work  is  defeated. 


ROCK  DRILLS  47 

At  most  mines  little  attention  is  paid  to  the  drill  bits  by  anyone  except  the 
blacksmith.  The  drill  runner  is  satisfied  if  the  bits  run  out  a  change  and  hold 
gage  well  for  the  next  bit  to  follow.  The  fewer  changes,  the  better  he  likes  it. 
The  same  is  true  of  the  blacksmith.  The  longer  a  bit  is  in  service  the  less 
frequently  must  it  be  sharpened.  The  bit  is  designed  for  use  as  long  as  possible 
without  resharpening  and  the  cutting  properties  take  second  place. 

In  designing  a  good  bit  both  cutting  and  staying  properties  should  be  con- 
sidered, but  the  day  of  hand-sharpening  and  of  chuck  bolts  is  rapidly  passing, 
and  now  the  efficiency  sacrificed  to  staying  properties  is  determined  largely  by 
the  cost  of  transportation  and  handling  of  bits  and  permissible  loss  of  gage.  It 
is  not  influenced  to  the  same  extent  as  formerly  by  the  labor  of  sharpening  or 
trouble  of  changing  bits.  The  cost  of  transportation  and  handling  of  bits 
amounts  to  a  considerable  item  which  increases  as  the  lasting  qualities  of  the 
bit  are  replaced  by  cutting  qualities,  so  that  it  often  governs  the  extent  to  which 
the  design  may  be  changed. 

Light,  compact  mechanical  sharpeners  can  now  be  obtained  at  a  reasonable 
price,  and  as  these  machines  reduce  the  cost  of  sharpening  to  a  low  figure  and 
enable  the  blacksmith  to  make  several  hundred  bits  per  day,  shop  considerations 
offer  no  serious  reason  for  retaining  merely  staying  qualities  in  the  design  of  the 
bit.  Nearly  all  rock  drills  can  be  provided  with  a  wedge  chuck,  or  some  means 
of  holding  the  bit  behind  chuck  keys  so  that  bits  can  be  changed  in  a  fraction  of 
a  minute.  This  largely  overcomes  the  objection  to  short  bits.  In  several  mines 
the  cost  of  transportation  and  handling  of  bits  is  greatly  reduced  by  installing 
the  power  sharpener  with  oil  or  coke  furnaces  underground. 

Allowable  loss  of  gage  is  an  important  factor,  for  the  greater  the  loss  the 
larger  must  be  the  diameter  of  the  shorter  bits  to  insure  a  certain  diameter  of 
hole  at  a  fixed  depth.  This  larger  diameter  means  a  loss  of  power,  so  this 
point  can  never  be  lost  sight  of  in  determining  the  bit  to  be  used.  Operators 
who  believe  the  gage  should  be  retained  irrespective  of  the  amount  of  power  used, 
run  the  edges  of  the  wings  of  the  bit  back  about  i  in.  in  a  line  parallel  to  the 
axis,  making  the  bit  a  reaming  tool.  If  this  is  done,  as  soon  as  the  cutting 
edges  wear  a  little  the  shoulders  begin  to  bind  and  stick  against  the  sides  of  the 
hole,  and  it  must  be  reamed  out  to  a  size  which  will  allow  the  bit  to  move  for- 
ward. When  such  a  bit  is  removed  from  the  hole  it  will  show  greater  wear  on 
the  edges  of  the  wings  than  on  the  cutting  edges.  As  the  bit  is  apparently  as 
hard  1/2  in.  back,  as  on  the  cutting  edge  it  is  reasonable  to  suppose  that  there 
has  been  as  much  work  done  in  wearing  the  steel  of  the  wings  as  in  wearing  an 
equal  amount  at  the  cutting  edge,  that  is,  if  the  reaming  edges  show  more  wear 
than  the  cutting  edges,  it  is  to  be  supposed  that  they  have  done  at  least  as  much 
work  as  the  latter.  In  other  words,  as  much  if  not  more  power  has  been  ex- 
pended in  reaming  the  hole  as  in  cutting  it;  half  the  power  has  been  used  in 
cutting  an  area  of  say  7  sq.  in.,  that  of  a  3-in.  circle,  and  half  the  power  has  been 
used  in  reaming  an  area  of  a  little  more  than  1/2  sq.  in.,  the  area  of  the  i/i6-in. 


48  HANDBOOK  OF  MINING  DETAILS 

rings  reamed  out.  Furthermore,  the  rock  drill  is  designed  to  cut  rock  by  means 
of  a  blow.  It  is  not  a  reaming  machine,  and  as  soon  as  a  bit  is  cutting  or 
reaming  the  side  of  the  hole  it  is  retarding  the  action  of  the  drill.  This  strains 
the  rotation  and  has  a  tendency  to  twist  and  break  the  bit.  Power  expended 
in  reaming  is  power  lost.  From  this  it  is  apparent  that  because  of  the  rapid  loss 
of  power  and  the  wear  and  tear  on  the  rock  drill,  little  of  the  efficiency  of  the 
bit  should  be  sacrificed  to  the  reaming  qualities. 

It  is  sometimes  claimed  that  unless  the  bit  has  reaming  edges,  the  hole  will 
become  rifled.  This  was  true  to  some  extent  when  the  bits  were  forged  by  hand, 
but  it  was  due  to  the  difficulty  of  getting  each  corner  or  wing  equidistant  from 
the  center  of  the  bit.  With  most  power  sharpeners  this  difficulty  is  removed, 
and  with  the  correctly  formed  bits  there  is  little  trouble  from  rifling. 

While  it  is  true  that  one  bit  cannot  be  selected  as  a  standard  for  any  and 
all  classes  of  rock,  still  the  power-sharpener  manufacturers,  especially  those 
who  have  gone  into  the  study  of  drill  bits,  are  gradually  working  toward  a 
few  standard  types.  The  consensus  of  opinion  is  that  under  average  conditions, 
a  good  bit  for  power-drilling  work  should  embody  the  following  points: 

(1)  It  must  take  full  advantage  of  the  chipping  and  fracturing  of  the  rock. 
In  a  bore  hole  there  is  a  certain  depth  to  which  rock  will  fracture  when  struck  by 
a  sharp  tool.     If  the  tool  is  driven  deeper  than  this  it  will  not  fracture  the  rock ;  it 
will  crush  it.     If  the  cutting  edge  of  the  bit  is  blunt  it  will  not  get  full  advantage 
of  the  fracture,  and  considerable  of  the  force  will  be  expended  in  crushing  or 
pulverizing.     The  bit  acts  as  a  wedge. 

(2)  The  wings  of  the  bits  should  be  as  thin  as  is  consistent  with  standing-up 
quality  to  allow  for  the  ejection  of  the  cuttings.     If  the  wings  are  left  heavy 
there  is  little  space  for  the  escape  of  cuttings  and  consequently  they  are  held 
in  front  of  the  bit  and  continually  churned  and  ground,  the  bit  does  not  easily 
reach  solid  rock  and  the  blow  loses  a  large  proportion  of  its  cutting  power 
before  it  reaches  the  rock. 

(3)  The  bit  must  be  perfectly  free  in  the  hole  at  all  times;  because  of  the 
tendency  of  the  rock  to  fracture,  the  drill  hole  will  be  a  trifle  larger  than  the  cut- 
ting edge.     If  the  bit  is  so  designed  that  the  cutting  edge  is  its  greatest  diameter 
and  will  practically  remain  so  until  dull,  it  will  always  remain  free  in  the  hole. 

(4)  The  bit  must  allow  equal  wear  on  all  corners.     If  the  bit  is  not  sym- 
metrical, that  is  if  the  ends  of  all  the  cutting  edges  are  not  the  same  distance  from 
the  center  of  the  bit,  the  longest  end  will  cut  a  groove  in  the  side  of  the  bore 
hole  and  a  rifled  hole  will  result.     Furthermore,  the  wear  is  unequal  and  the 
extra  strains  in  the  steel  often  break  it.     The  rotation  of  the  drill  is  impeded  and 
the  parts  subjected  to  excessive  wear. 

(5)  The  bit  must  be  dressed  in  a  manner  consistent  with  the  treatment  of 
good  steel.     It  must  not  be  overheated,  or  worked  while  too  hot.     Light  rapid 
blows  should  be  used  in  forging.     The  bit  must  be  tempered  properly.     The 
proper  temper  should  be  determined  by  experiment  and  rigidly  adhered  to.     The 


ROCK  DRILLS 


49 


bit  should  be  allowed  to  cool  thoroughly  after  forging  and  should  then  be  re- 
heated for  tempering.  It  should  never  be  sharpened  and  tempered  on  the  same 
heat. 

In  Fig.  19  are  shown  bits  designed  to  fill  these  requirements.  An  angle  of 
about  90°  for  the  cutting  edge  is  generally  accepted  as  the  correct  angle.  If  the 
angle  is  greater  the  bit  has  a  tendency  to  crush  rather  than  fracture  the  rock, 
and  as  a  rule  the  bit  cuts  slowly.  An  angle  less  than  90°  gives  a  bit  which  will 
cut  fast,  but  it  has  a  tendency  to  break  off  and  wear  rapidly.  There  is  also  a 
tendency  for  it  to  enter  the  rock,  especially  soft  rock,  past  the  point  of  fracture, 
and  expend  energy  in  crushing  or  wedging  out  the  rock.  The  "mudding" 
powers  are  greatly  diminished.  The  thickness  of  the  wings  may  range  from 
3/4  in.  on  a  large  steel,  to  3/8  in.  or  even  less  on  a  stoper  and  hammer-drill  bit. 
The  wing  must  not  be  so  thin  that  it  breaks  off,  still,  the  less  stock  necessary  the 
better  the  clearance  for  the  cuttings. 


CORRECTLY   MADE   BITS.  INCORRECTLY   MADE    BITS. 

FIG.    19. — DESIGNS   OF   DRILL  BITS. 

The  third  point  is  probably  the  hardest  to  comply  with.  When  the  bits 
shown  in  Fig.  19  are  first  placed  in  the  hole  the  cutting  edge  is  the  largest 
diameter,  and  as  it  may  be  safely  assumed  that  the  rock  will  fracture  1/16  in. 
beyond  the  bit,  the  latter  must  be  free  in  the  hole.  The  wings  of  the  bit  taper 
in  the  ratio  of  one  to  four,  or  one  to  five,  and  as  the  cutting  edge  wears,  a  shoulder 
or  reaming  edge  forms  on  the  wing.  When  it  wears  between  1/16  and  1/8  in. 
from  each  wing,  a  shoulder  i  /  4  to  5  /  8  in.  forms  and  there  is  a  point  between  these 
where  the  cutting  edge  is  fracturing  the  rock  in  the  side  of  the  hole  to  a  diameter 
equal  to  the  diameter  of  the  bit  through  the  shoulders.  In  other  words,  the 
shoulders  of  the  bit  are  just  touching  the  sides  of  the  hole.  If  the  bits  run  past 
this  point,  the  cutting  edge  will  not  cut  the  hole  to  a  diameter  large  enough  to 
admit  the  bit  and  the  shoulders  immediately  become  reaming  surfaces. 

The  taper  of  i :  4  or  i :  5  is  determined  upon  as  a  medium.  If  less  taper  is 
used,  say  1:7,  the  shoulders  become  more  prominent  and  the  cutting  edge  has 
less  allowable  wearing  surface  before  the  bit  binds  in  the  hole  causing  the 
shoulders  to  become  reaming  surfaces.  If  the  wings  have  a  greater  taper,  say 
1:2,  the  wear  is  excessive,  and  the  loss  of  gage  prohibitive.  The  sharp  taper 
4 


50  HANDBOOK  OF  MINING  DETAILS 

leaves  the  ends  of  the  cutting  edge  in  a  weakened  condition  and  they  easily 
break  up  and  chip  off. 

The  necessity  for  having  the  drill  bit  concentric  is  obvious.  In  hand  sharp- 
ening and  even  with  some  power  sharpeners  it  is  not  uncommon  to  find  one  of 
the  ends  of  the  cutting  edges  protruding  1/32  to  1/16  in.  beyond  the  others. 
Some  sharpener  manufacturers  have  effectively  overcome  this  difficulty  by 
entirely  inclosing  the  bit  under  a  heavy  pressure  while  it  is  being  forged.  When 
this  is  done  there  can  be  no  question  as  to  the  corners  falling  within  a  circle. 

The  tempering  and  manner  of  heating  and  treating  the  bit  is  generally  left 
to  the  discretion  of  the  blacksmith.  This  is  a  mistake,  as  a  little  attention  and 
study  given  the  subject  by  the  manager  or  superintendent  will  often  result  in 
marked  improvements.  Many  kinds  of  steel  now  on  the  market,  and  the  scien- 
tific methods  of  treatment  are  entirely  new  to  the  average  smith. 

A  word  should  be  said  about  mechanical  sharpeners.  These  machines 
have  been  greatly  improved  in  the  last  few  years,  and  now  extremely  light, 
simple  designs  of  remarkably  high  capacity  and  efficiency  are  within  the  reach 
of  all.  The  bits  dressed  in  the  sharpener  are  always  perfect  in  form  and  gage 
and  everything  considered,  will  give  from  25  to  50%  greater  efficiency  than 
if  sharpened  by  hand.  In  addition  to  the  increased  speed  of  drilling  there  is  a 
noticeable  saving  in  the  wear  and  breakage  of  machine  parts  and  the  bit 
itself  lasts  longer  and  wears  much  better. 

When  installing  a  power  sharpener  one  should  not  lose  sight  of  its  main 
advantage,  increasing  the  efficiency  of  the  drill  bit.  It  should  be  installed  with 
the  idea  that  because  of  the  marked  reduction  in  the  cost  and  time  of  sharpening 
one  can  afford  to  furnish  the  drill  with  better  steel  more  often.  It  is  impossible 
to  make  a  hard  and  fast  rule  as  to  when  a  power  machine  should  be  installed, 
but  it  is  certain  that  a  sharpener  will  effect  a  material  reduction  in  cost  per  steel 
dressed,  lessen  the  machine  repair  parts  required,  save  steel  and  steel 
breakage,  and  greatly  increase  the  drilling  speed  of  machines. 

Rand  Drill  Steel  and  Bits  (By  E.  M.  Weston).— Tests  have  recently  been 
made  by  Robert  Allen  at  the  Robinson  Deep  mine  to  determine  the  most 
suitable  steel  for  making  drills  for  use  in  the  Rand  mines.  Many  varieties  of 
steel  have  been  tested  in  the  following  way.  From  40  to  60  drills  made  from 
each  brand  of  steel  were  sharpened  by  hand,  weighed,  measured  by  a  microm- 
eter gage,  then  sent  to  the  mine  where  they  were  used  in  2  3/4-in.  machines  to 
drill  the  hardest  rock.  The  depth  of  holes  drilled  and  time  taken  were  noted. 
The  drills  were  then  sent  to  the  surface  where  they  were  again  weighed  and 
measured  and  the  quality  of  the  steel  compared  by  the  loss  in  gage.  It  is 
difficult  to  convince  the  Rand  miners  that  the  proper  heating  and  tempering  of 
the  steel  has  an  important  bearing  on  the  efficiency  of  the  drills,  so  it  was  neces- 
sary to  recommend  steel  of  such  carbon  content  as  would  permit  of  direct  plunging 
in  the  type  of  tank  giving  a  limited  depth  of  immersion  for  cross  bits.  The  bits 
as  finally  adopted,  are  shown  in  Fig.  20.  They  are  used  in  2  1/2-  and  2  3/4-in. 


ROCK  DRILLS  51 

machines.  The  starting  bit  is  used  to  drill  15  in.  of  hole,  the  second  21  in.,  and 
the  third  and  fourth  24  in.  each.  With  higher  air  pressure  I  believe  that  the 
third  and  fourth  bits  should  be  made  of  i-in.  steel,  as  even  with  70  Ib.  air  pres- 
sure a  2  3/4-in.  machine  will  bend  some  of  the  7/8-in.  drills.  A  carbon  content 
of  from  0.7  to  0.75%  is  the  highest  that  will  permit  of  steel  being  satisfactorily 
welded  and  which  will  temper  without  cracking  on  direct  plunging. 


Starter. 


Second. 


FIG.    2O.  —  DRILL   BITS   USED    ON  THE   RAND. 


Ejecting  Sludge  from  Drill  Holes  (By  E.  M.  Weston).—  A  method  of 
ejecting  mud  and  cuttings  from  a  drill  hole  has  been  devised  by  Mr.  Tippet,  an 
Australian,  that  may  result  in  making  it  possible  to  use  a  one-man  drill  in  the 
mines  of  the  Rand.  He  conceived  the  idea  of  withdrawing  the  sludge  through, 
instead  of  forcing  water  down  hollow  steel.  He  intended  to  bring  the  sludge 
right  through  the  machine  by  means  of  a  suction  device  which  was  to  be  worked 


FIG.    21. — HOLLOW-STEEL   BIT   WITH   SIDE    OPENING. 

by  the  exhaust  air.  While  using  a  rose  bit,  he  noted  that  when  the  suction  was 
not  operating,  the  drillings  were  being  vigorously  ejected.  The  sludge  evidently 
entered  the  hollow  in  the  steel  with  considerable  velocity  on  the  down  stroke, 
the  inertia  of  which  was  not  entirely  overcome  during  the  period  of  the  return 
stroke.  All  that  is  necessary  to  take  advantage  of  this  effect  is  to  employ  hollow 


52  HANDBOOK  OF  MINING  DETAILS 

steel  and  forge  a  collar  near  the  shank,  then  to  drill  a  transverse  hole  to  connect 
with  the  central  channel  at  a  point  just  below  the  chuck.  Steel  of  this  construc- 
tion has  been  found  to  hold  its  gage  remarkably  well.  The  steel  used  with 
piston  drills  is  i  i/4-in.  diameter,  through  which  passes  a  3/4-in.  channel. 
The  central  channel  becomes  filled  with  sludge  but  does  not  choke  with  pieces  of 
rock  (granite)  even  when  as  large  as  a  ten-cent  piece.  Fig.  21  shows  the  trans- 
verse and  longitudinal  passages  of  the  improved  drill  steel. 

Improved  Chuck  for  Piston  Drills. — In  the  North  Star  mines,  at  Grass 
Valley,  Calif.,  a  special  type  of  chuck  designed  by  Messrs.  Paynter  and  Bastian, 
employees  of  the  company,  is  used  on  the  piston-machine  drills.  The  peculiarity 


Cross  Section  on  Line  w-Jfr 
Gib  and  Key,  but  not 
Bushing  Key,  shown. 


Cross  Section  on  Line  w-n 
Gibs  and  Keys  not  shown . 

FIG.    22. — NORTH   STAR   BOLTLESS   CHUCK   FOR   PISTON    DRILLS. 

of  the  chuck  is  that  it  includes  no  bolts,  and  hence  does  not  require  the  use  of  a 
wrench  for  tightening  the  grip  upon  the  drill  shank.  The  working  drawing, 
Fig.  22,  shows  the  details  of  the  chuck  and  clamping  arrangement.  The  chuck 
is  drilled  as  usual  to  receive  the  shank  of  the  drill  steel.  A  slot,  above  and 
parallel  to  the  shank  of  the  steel,  is  cut  in  the  chuck  to  receive  a  gib  A  that  bears 
against  the  shank  of  the  drill.  Below  the  drill  socket  and  perpendicular  to  the 
axis  of  the  chuck  two  holes  are  cut  to  receive  bushing  keys  X  and  Y,  that  bear 
against  either  end  of  the  lower  part  of  the  drill  shank  and  take  up  wear  from 
the  chuck.  A  strap  or  band  C  fits  around  the  chuck  and  over  a  tapered  key  B 
that  bears  on  the  gib  A .  The  key  B  is  tapered  away  from  the  end  of  the  chuck 
so  that  as  every  impact  of  the  drill  against  rock  drives  it  further  under  the  strap 
C,  the  gib  is  forced  more  tightly  against  the  drill  shank.  There  is,  hence,  no 
tendency  of  the  drill  to  become  loose  in  the  chuck.  On  the  other  hand,  it  is 
held  more  securely  at  each  stroke.  The  key  B  is  made  with  a  heavy  head  at 
either  end.  To  fasten  the  drill  in  the  chuck  the  key  is  driven  tight  by  a  blow 


ROCK  DRILLS 


53 


upon  the  head  at  the  larger  end.  A  blow  on  the  other  end  of  the  key  serves  to 
loosen  it  and  allows  the  drill  to  be  removed.  This  type  of  chuck  has  been  used  for 
several  years  in  the  North  Star  mines  and  has  proved  entirely  satisfactory.  Its 
advantage  over  the  ordinary  type  where  bolts  have  to  be  drawn  tight  every  few 
minutes  should  be  evident.  The  construction  embodies  no  particular  difficulties. 
Shaping  Chuck  Bolts  (By  H.  Lawrence  Brown). — The  accompanying 
sketch,  Fig.  23,  shows  a  device  for  making  chuck  bolts  for  machine  drills.  It 
consists  of  the  plate  B,  made  of  i-in.  iron,  bolted  to  a  work  bench  by  3/4-in. 
countersunk  bolts  A.  To  the  plate  are  riveted  the  pieces  C  and  D,  of  i-in. 


O-A 

; 

O 

n    ' 

T          AO 

3 

D 

O 

a 

3 

0 

/ 

c 

o 

\t 

O-A 

o 

AO 

f 

FIG.    23. — DEVICE    FOR   SHAPING   CHUCK   BOLTS. 

material,  with  a  curve  in  the  piece  C  corresponding  with  the  bend  desired  in 
the  chuck  bolt.  The  levers  F  are  about  2  ft.  long  and  are  offset  as  shown  at 
E,  where  the  thread  on  the  bolt  begins,  in  order  not  to  injure  the  threads 
while  the  bolt  is  being  shaped.  The  threaded  bolt  is  heated  and  placed 
between  C  and  D,  while  the  levers  are  open.  Closing  the  levers  to  the  posi- 
tion shown  bends  the  bolt  to  the  proper  shape. 

Improved  Drill  Post  Collar  (By  Albert  Mendelsohn). — An  improved  post 
collar  now  being  used  in  some  of  the  copper  mines  of  Lake  Superior  is  shown 
in  Fig.  24.  It  does  away  entirely  with  the  two  bolts  of  the  collar  at  present 
in  general  use,  and  can  be  loosened  or  tightened  by  a  single  blow  of  the  miner's 
wrench.  It  consists  of  a  cast-steel  band  A  of  diameter  slightly  greater  than 
that  of  the  post.  A  tool-steel  gib  B  fits  into  a  slot  in  the  band,  and  directly 
over  the  gib  a  wedge-shaped  key  C  of  the  same  material  is  driven.  The  inner 
face  of  the  gib  is  shaped  to  an  arc  of  the  same  radius  as  the  post  and  when 


54 


HANDBOOK  OF  MINING  DETAILS 


the  wedge  is  struck  on  its  wide  end  the  gib  is  forced  tightly  against  the  post. 
An  advantage  of  this  collar  over  the  one  at  present  in  general  use  is  that  time 
and  work  are  saved,  because  there  are  no  bolts  to  tighten  and  loosen.  This  time 
may  not  amount  to  much  on  a  two-man  machine,  but  with  the  introduction  of 
the  one-man  " butterfly"  drill  and  the  attention  to  details  necessary  in  running 
it,  any  device  that  will  save  two  or  three  minutes  per  hole  drilled  is  of  importance. 
At  present  the  miner  using  a  one-man  machine  has  to  adjust  nine  bolts;  the 
elimination  of  two  is,  therefore,  no  small  item.  Another  advantage,  and  one 
which  is  of  importance  on  one-man  machines,  is  the  fact  that  this  improved 


FIG.    24. — DRILL-POST   COLLAR   WITHOUT   BOLTS. 


collar  can  be  rapidly  loosened  and  tightened,  and  if  necessary  with  one  hand. 
In  raising  the  machine  on  the  post,  if  the  post  is  wet  or  the  machine  too  far 
in  on  the  arm,  the  arm  will  not  catch  on  the  post.  This  means  that  the  machine 
and  arm  must  be  held  in  the  elevated  position  while  the  collar  is  loosened, 
slid  up  the  post  under  the  arm  and  tightened.  In  any  case,  speed  is  desirable 
under  these  conditions,  and  with  a  one-man  machine  it  is  imperative.  Inci- 
dentally, it  might  be  mentioned  that  these  collars  were  used  with  the  two 
one-man  machines  with  which  four  men  recently  drove  285  ft.  of  6Xy-ft. 
drift  in  one  month;  exceptional  drifting  for  the  copper  country. 

Drill  Post  with  Removable  Screw.— In  the  Copper  Range,  Hancock  and 
Quincy  mines  single-screw  posts,  the  jack  screws  of  which  are  removable,  are 
used  whenever  a  single-screw  post  is  required  in  making  a  cross-bar  setup  with 
a  machine.  The  details  of  the  screw  are  shown  in  Fig.  25.  The  device  has 
even  been  used  in  shaft  sinking  and  is  said  to  have  proved  as  satisfactory  for  that 


ROCK  DRILLS 


55 


work  as  an  ordinary  post,  while  it  possesses  the  advantage  that  owing  to  the 
fact  that  the  screw  feeds  ahead  instead  of  the  jacking  nut,  as  is  the  case  in  the 
ordinary  single-screw  post,  the  screw  can  be  stuck  into  a  hole  in  the  wall,  and  the 
bar  jacked  without  any  trouble  arising  from  projections  from  the  wall  inter- 
fering with  jacking.  The  separate  screw  and  nut  also  possess  the  advantage 
that  such  a  single-screw  jack  can  be  used  with  several  different  lengths  of  bars. 
The  nut  of  the  jacking  device  is  octagonal  in  shape  with  four  steel-bushed 
holes  in  its  sides  for  receiving  the  jacking  bar,  and  one  end  of  the  nut  is  made 
big  enough  to  go  over  the  end  of  the  post  as  a  collar.  The  screw  has  a  blunt 
end  that  goes  against  the  ground,  while  in  it  is  a  keyway  that  goes  over  three 


I  Two  threads  per  inch. 


Hardened  steel  bashing. 
S-KejB  to  prevent  screw  from  turning 
%-la.stud3  screwed  in  and  ailed  to  form  key  for  screw. 


Head  shrank  in 


Soft  steel  bashing  shrunk  it 


FIG.    25. — DETAILS   OF   DRILL   COLUMN   WITH   REMOVABLE    SCREW. 

lugs  in  the  end  of  the  post  so  as  to  keep  the  screw  from  twisting  with  respect  to  the 
post  as  the  jacking  nut  is  turned.  The  post  has  at  one  end  the  ordinary  toothed 
head  shrunk  on  it,  while  at  the  other  there  is  a  soft-steel  bushing  or  guide 
shrunk  in  for  the  screw.  Through  this  end  of  the  bar  three  holes  are  drilled 
and  tapped  for  y/S-in.  studs.  These  studs  are  screwed  in  tightly  and  then  filed 
flat  to  serve  as  the  keys  to  go  into  the  keyway  in  the  jacking  screw,  as  well  as 
to  hold  in  the  guide  bushing.  The  barrel  of  the  post  is  a  piece  of  ordinary  4-in. 
gas  pipe. 

Jack  for  Machine  Drill  Columns. — Machine-drill  jacks  become  quite 
heavy  as  the  length  of  the  column  increases,  especially  when  a  column  with 
two  jack  screws  is  used.  In  the  Michigan  copper  country,  machines  have  to  be 
set  up  with  columns  as  long  as  13  ft.  It  therefore  becomes  important  to  make 
them  as  light  as  possible,  especially  now  that  one-man  machines  are  being 
introduced.  In  driving  drifts  it  is  often  desirable  to  have  two  lengths  of  column; 
in  such  a  case  the  Osceola  type  of  machine  column,  in  which  the  jack  proper  is 
in  one  piece  and  the  post  in  another  that  can  be  lifted  out  of  its  socket  in  the 
jack,  is  convenient.  When  the  post  has  to  be  moved,  the  weight  to  be  lifted  is 
divided  in  two  as  the  two  parts  are  moved  separately.  At  the  Osceola  and  the 
Calumet  &  Hecla  mines,  the  post  consists  of  an  ordinary  4-in.  gas  pipe  for 


56  HANDBOOK  OF  MINING  DETAILS 

both  two-man  and  one-man  machines,  with  a  light  cast-iron  cap  fastened  to  the 
upper  end.  In  the  bottom  of  this  pipe  a  notch  is  cut  to  fit  over  the  lug  in  the 
bottom  of  the  socket  hole  of  the  jack.  Fig.  26  shows  the  design  of  this  screw 
part,  which  is  cast  in  one  piece  with  socket  holes,  into  which  the  nuts  of  the 
jack  screws  are  fastened.  The  lug  on  the  bottom  of  the  post  socket  is  now  cast 
square,  but  in  the  future  it  is  probable  that  it  will  be  cast  with  a  V-section,  so  that 


FIG.    26. — CAST-IRON-  JACK  FOR  A  DRILL  COLUMN. 

the  notches  in  the  bottom  end  of  the  post  can  be  cut  to  fit  tight,  for  often  at 
present  these  notches  in  the  post  are  cut  too  wide,  allowing  the  post  to  turn 
slightly  when  the  machine  is  started  and  throwing  the  hole  slightly  out  of  align- 
ment. Such  a  machine  jack  can  be  made  cheaply,  as  there  is  no  machine  work 
on  the  casting,  while  its  use  is  a  great  advantage  where  a  two-post  jack  is  re- 
quired for  one-man  drills. 


POINTERS  ON  OPERATION 

Removing  Stuck  Drills. — In  drilling  deep  holes  by  hand  with  15-  or  20-ft. 
steel,  the  steel  often  sticks;  or,  in  some  cases,  a  drill  is  actually  driven  in  soft 
ground  as  one  would  drive  a  stake,  and  then  it  becomes  necessary  to  resort  to 
some  means  to  remove  it.  This  may  be  done  easily  by  taking  a  piece  of  steel 
i  1/4  or  i  1/2  in.  thick,  6  in.  square,  with  a  hole  in  the  center  about  twice  the 
size  of  the  drill.  This  is  placed  over  the  head  of  the  drill  and  two  steel  wedges 
driven  in,  to  fasten  the  piece  of  steel  on  the  drill,  thus  forming  a  good  shoulder 
against  which  to  hammer.  A  few  blows  on  this  will  soon  loosen  the  drill.  It 
is  much  more  effective  than  a  chain  and  lever,  or  pulley  block. 

Wrench  for  Removing  Stuck  Drills  (By  Claude  T.  Rice). — A  miner 
often  loses  an  hour  or  two  through  the  sticking  of  a  drill  in  a  deep  hole.  The 


ROCK  DRILLS 


57 


fault  is  usually  the  miner's.  A  small  quantity  of  sticky  drillings  will  wedge  a 
drill  so  that,  unless  there  is  a  good  wrench  for  twisting  it  out  through  the 
drillings,  it  cannot  be  removed,  and  a  new  hole  must  be  drilled.  Cruciform 
steel  has  less  tendency  to  stick  in  damp  holes  than  octagonal  or  hexagonal  steel, 
as  the  ribs  act  like  a  conveyor  to  eject  the  drilling,  provided  that  the  hole  is  not 
too  flat  and  the  drillings  are  not  too  sticky.  E.  M.  Weston  has  advised  the  use 


FIG.    27. — A   DRILL-TWISTING   WRENCH. 

of  drill  steel  with  a  rolled  screw  to  overcome  this  difficulty  and  on  the  Fort 
Wayne  electric  drill,  bits  with  twisted  shanks  are  used.  Similar  steel  was  used 
a  few  years  ago  with  good  results  in  piston  drills  in  certain  of  the  New  York 
iron  mines.  Twisted  drill  steel  does  not  stick  in  a  hole,  I  understand,  but  it  is 
expensive  and  probably  not  so  satisfactory  as  octagonal  or  cruciform  steel. 

The  most  satisfactory  wrench  that  I  have  seen  for  twisting  drill  steel  from  a 
hole  is  that  in  use  in  the  Calumet  &  Hecla  mines  and  shown  in  Fig.  27.  It  is 
made  of  3/4-in.  iron  and  consists  of  a  frame  to  which  one  of  the  toothed  jaws  is 


FIG.    28. — COTTER   WRENCH   FOR   STUCK   DRILLS. 

fastened ;  the  other  slides  loosely  in  the  slot  of  the  frame,  being  prevented  from 
slipping  out  by  shoulders.  Back  of  the  loose  jaw  is  a  key,  prevented  from 
falling  out  by  a  pin  through  its  small  end.  This,  driven  downward  by  a  hammer, 
forces  the  teeth  of  the  jaws  into  the  drill  steel  so  as  to  grip  securely.  The  ex- 
tension of  the  frame  forms  a  handle  18  in.  long,  but  in  case  this  is  not  long 
enough,  a  piece  of  pipe  can  be  slipped  over  it.  The  wrench  is  simply  and 


58  HANDBOOK  OF  MINING  DETAILS 

strongly  made,  so  that  it  can  be  hammered,  twisted,  and  jerked  without  injury. 
It  has  been  in  use  for  several  years  at  the  Calumet  &  Hecla  mines  and  has 
proved  satisfactory. 

In  Fig.  28  is  shown  the  design  of  the  wrench  that  is  used  at  the  Mohawk 
mine  in  Michigan  to  aid  in  loosening  drills  that  become  jammed  in  bore  holes. 
The  wrench  is  quite  similar  to  the  one  that  is  used  at  the  Calumet  &  Hecla 
mines.  The  grip  on  the  drill  is  obtained  by  driving  in  a  key  or  cotter  that 
grips  the  drill  between  itself  and  the  jaw  of  the  wrench.  The  wrench  is  much 
heavier,  and  does  not  seem  to  be  quite  as  handy  as  the  one  used  at  the  Calumet 
&  Hecla  mines.  In  working  the  drill  out  a  chain  is  fastened  to  the  drill,  thence 
it  is  passed  around  the  machine  post.  One  man  pulls  on  the  chain  while  the 
other  twists  the  drill  with  the  wrench. 

Wrinkle  for  Piston  Drill.  —  It  is  frequently  necessary  for  a  machine-man 
to  release  his  hold  on  the  crank  to  throw  water  into  a  hole  or  attend  to  the  many 
little  details  that  are  constantly  requiring  his  attention,  and  a  freely  feeding 
drill  will  crank  itself  back  too  rapidly  to  permit  its  being  left.  Miners  often 
hang  a  wrench  on  the  crank  or  lean  a  piece  of  steel  against  it  or  twist  the  hose 
around  it.  The  last  two  expedients  are  unhandy  and  inconvenient;  any  weight 
hung  on  the  crank  will  slip  off  unless  the  drill  is  inclined  steeply  downward. 
A  hole  drilled  through  the  crank  at  the  base  of  the  handle,  through  which  a 
wire  may  be  slipped  to  hold  the  weight  will  expedite  the  miner's  work  consider- 
ably and  do  away  with  the  temptation  to  allow  the  feed  to  work  stiffly.  A 
couple  of  7/8-  or  i-in.  nuts  bound  closely  to  the  crank  in  this  manner  will  not 
slip  around  or  get  tangled  with  the  crosshead. 

Cleaning  Drill  Holes  (By  J.  H.  Forell).—  In  drilling  upward  slanting  back 
holes  in  dry  ground,  the  drillings  are  often  removed  by  a  squirt  gun,  an  improved 


Ed.  Iron 


Thread 

244Q, «j  i^-iti.  Sq.  \VeldedShoulder 

Iii.  Hole 

FIG.    29. — SQUIRT   GUN  FOR  CLEANING  DRILL  HOLES. 

form  of  which  is  shown  in  Fig.  29.  A  piece  of  i-in.  black  pipe,  20  to  24  in. 
long,  is  threaded  at  one  end.  A  cap,  slightly  cone-shaped  at  one  end,  is  turned 
on  a  lathe  and  threaded  at  the  large  end  to  fit  the  i-in.  pipe;  the  small  end  is 
tapped  to  receive  a  i/4-in.  pipe  16  to  24  in.  long.  The  outer  end  of  the  i/4-in. 
pipe  is  threaded  internally  to  hold  a  plug  through  which  passes  a  i/i6-in.  hole. 
The  i/4-in.  pipe  is  curved  to  enable  the  operator  to  introduce  it  into  the  hole 
without  danger  of  being  struck  by  the  chuck  of  the  machine.  The  plunger  is 
made  of  3/8-in.  round  iron  and  is  packed  with  cotton  candle- wicking  held 
between  two  shoulders  of  i/4-in.  square  iron  about  4  in.  apart.  The  advantage 


ROCK  DRILLS  59 

of  this  squirt  gun  is  in  the  long,  narrow  pipe,  which  can  be  introduced  into  the 
hole  a  foot  or  more,  giving  a  greater  pressure  at  the  cutting  end  of  the  hole, 
whereas,  with  the  old-style  gun  the  greatest  pressure  was  near  the  collar. 

Preventing  Freezing  of  Air  Exhaust. — Alcohol  is  used  to  prevent  freezing 
at  the  exhaust  of  the  air-operated  shot  drills  in  use  at  the  site  of  the  new  station 
in  New  York  of  the  New  York  Central  railroad.  This  company  has  had  to 
do  an  enormous  amount  of  core  drilling  within  the  last  15  years,  and  in  this 
work  several  types  of  drills  have  been  used.  One  of  the  most  interesting 
outcomes  of  the  work  is  the  freezing-prevention  appliance  that  can  be  readily 
adapted  for  use  on  any  small  air-operated  machine  where  trouble  is  experienced 
from  freezing  at  the  exhaust.  Alcohol  is  admitted  to  a  vertical  part  of  the  air- 
supply  pipe  and  close  to  the  machine.  The  device  used  for  feeding  the  alcohol 
is  attached  to  the  feed  pipe  as  is  a  lubricator.  It  consists  of  a  piece  of  i  i  /  2-in. 
pipe  about  12  in.  long,  fitted  with  bushings  at  the  top  to  take  a  piece  of  i/2-in. 
pipe  6  in.  long.  The  small  pipe  is  closed  by  a  valve.  The  other  end  of  the 
i  i /2-in.  pipe  is  fitted  with  bushings  to  take  a  3-in.  piece  of  i/2-in.  pipe,  to 
which  a  valve  and  an  elbow  are  attached  and  into  the  elbow  another  short 
piece  of  i/2-in.  pipe  is  screwed.  The  threaded  end  of  the  last-mentioned 
pipe  is  screwed  into  a  hole  tapped  into  the  air  pipe  so  that  when  screwed 
tight  the  i  i/2-in.  pipe  is  parallel  to  the  air  pipe.  By  opening  the  top  valve, 
the  i  i/2-in.  pipe  can  be  filled  with  alcohol.  That  valve  is  then  closed,  and, 
when  the  machine  is  operating,  the  lower  valve  is  opened  just  enough  to  permit 
drops  to  pass  slowly.  The  admixture  of  alcohol  vapor  in  the  air  effectually 
prevents  freezing  at  the  exhaust.  The  i  i/2-in.  pipe,  which  has  a  capacity 
of  about  i  pint,  is  usually  filled  with  alcohol  twice  per  shift. 

Cutting  Timber  by  Small  Hammer  Drills. — Small  hammer  drills  are  used 
with  a  chisel  bit  in  the  Hecla  mine  at  Burke,  Ida.,  for  cutting  oft"  the  crushed 
ends  of  timbers.  In  the  stopes  the  greatest  pressure  is  from  the  squeeze  of 
the  walls,  and  as  the  ends  of  the  stulls  and  caps  become  splintered  and  crushed, 
it  is  necessary  to  cut  them  off  and  put  in  new  blocking.  It  is  often  difficult  to 
get  at  the  crushed  timbers,  and,  even  when  accessible,  it  is  not  an  easy  job  to 
chisel  or  saw  the  wet  and  twisted  fibers  by  hand.  The  cutting  of  the  wood  is 
rendered  quite  easy  with  the  drills,  and  by  using  sufficiently  long  bits,  almost 
any  desired  place  can  be  reached.  The  drills  and  chisels  may  also  be  used 
to  great  advantage  for  chiseling  wall  plates  when  an  extra  shaft  compartment 
must  be  added,  or  in  cutting  off  posts  to  ease  up  drift  sets  in  heavy  ground. 
In  a  number  of  mines,  the  blocking  on  drift  caps  is  shot  out  when  it  is  neces- 
sary to  ease  up  on  the  sets;  this  work  can  much  more  safely  and  surely  be 
accomplished  with  the  drill. 

An  Air  Moil  for  Cutting  Timber  Hitches  (By  S.  H.  Hill).— In  the  Lake 
Superior  district  it  has  been  customary  to  cut  the  hitches  required  in  timbering 
by  hand,  usually  with  a  moil.  However,  since  a  great  number  of  first-class 
air  hammer  drills  have  come  upon  the  market  the  use  of  an  air  moil  for  this 


60  HANDBOOK  OF  MINING  DETAILS 

work  has  met  with  favor  upon  the  grounds  of  economy  and  speed.  The  air  moil 
can,  of  course,  only  be  used  in  headings  that  are  piped  for  air.  A  reducer  can 
be  used  on  the  end  of  the  pipe  and  air  for  the  hand  tool  taken  from  the  nipple  used 
for  heading  machines.  However,  this  necessitates  doing  the  hitch  cutting  or 
squaring  when  the  heading  machines  are  not  in  use  or  while  one  of  them  has 
been  purposely  stopped.  The  introduction  of  a  manifold  on  the  end  of  air 
pipe,  having  one  opening  especially  for  the  hand  tool  is  more  satisfactory. 
There  is  also  a  possibility  of  using  the  air  moil  in  sampling  breasts,  etc. 

Boring  Flat  Holes  with  Air  Hammer  Drills  (By  Clarence  C.  Semple).— 
In  the  smaller  mines  of  the  Cripple  Creek  district,  air-hammer  drills  are  used 
to  bore  flat  holes,  some  of  which  are  almost  horizontal.  The  cuttings  are 
removed  from  the  hole  by  a  blowpipe,  an  instrument  designed  for  the  purpose 
by  H.  E.  Harris,  the  local  agent  for  the  Waugh  drill.  The  blowpipe  consists 
of  a  brass  tube  1/8  in.  in  diameter  and  as  long  as  the  deepest  hole  drilled.  One 
end  of  the  tube  is  attached  to  a  short  piece  of  i/2-in.  hose  by  a  1/2-  to  i/8-in. 
bushing  and  a  hose  coupling;  the  other  end  of  the  hose  is  fitted  with  a  coupling, 
and  nipple  connecting  with  a  i/2-in.  valve.  The  air  hose  from  the  mains  con- 
nect with  the  air  inlet  of  the  drill  by  a  tee,  to  the  third  branch  of  which  the 
blowpipe  hose  and  valve  is  attached.  Cruciform  steel  is  used  and  the  blowpipe 
tube  is  extended  into  the  hole  between  two  of  the  lugs  of  the  steel,  where  it 
turns  easily  with  the  steel  without  catching  on  the  walls  of  the  hole  as  the  drill 
is  rotated.  The  quantity  or  air  necessary  to  blow  the  cuttings  from  the  hole  is 
regulated  by  the  valve  of  the  i/2-in.  hose.  The  blowpipe  makes  a  dusty 
working  face  if  the  ground  is  dry,  so  the  miners  usually  wear  respirators  or 
throw  a  little  water  into  the  hole  with  a  can.  It  is  also  possible  to  connect  the 
blowpipe  by  a  second  i/2-in.  hose  and  a  three-way  valve,  with  a  water  supply 
so  that  water  can  be  introduced  into  the  hole  to  allay  the  dust,  and  air  then  used 
only  to  blow  out  the  mud,  the  three-way  valve  being  used  to  control  the  flow  of 
water  or  air. 

[The  adaptation  of  air-hammer  drills  to  use  in  raises  and  drifts  is  brought 
out  in  articles  in  Chapters  IV  and  V. — EDITOR.] 

ECONOMICS  OF  PRACTICE 

Drilling  with  Double  Screw  Columns  (By  P.  B.  McDonald). — A  single- 
screw  column  or  bar,  rigged  horizontally,  is  of  course  invaluable  for  supporting 
a  machine  drill  over  a  pile  of  muck  in  a  drift;  in  some  cases,  it  is  more  easily 
handled,  due  to  its  length  coinciding  more  closely  with  the  width  of  the  work- 
ing than  the  double-screw  column  with  the  height.  Operators  often  purchase 
single-screw  columns  for  occasional  work  and  the  miners  get  into  the  habit  of 
using  them  generally  around  the  mine  because  they  permit  of  more  time  being 
wasted  in  clearing  away  muck. 

Under  ordinary  circumstances  better  results  can  be  obtained  if  the  muck  is 


ROCK  DRILLS  61 

cleaned  out  promptly,  and  the  drilling  done  on  double-screw  columns  rigged 
vertically  with  an  arm.  Due  to  the  extra  movement  permitted  by  the  arm,  the 
holes  can  be  placed  with  greater  accuracy  and  convenience.  When  men  can 
conveniently  place  holes  where  their  judgment  directs,  there  is  less  chance  of 
the  cut  failing  to  break.  For  the  same  reason  it  may  be  possible  to  break  the 
cut  with  one  or  two  holes  less  than  would  be  required  with  the  horizontal  bar, 
which  does  not  allow  much  leeway  in  the  movement  of  the  drill. 

When  a  horizontal  bar  is  used,  the  setup  has  sometimes  to  be  made  a  few 
inches  too  far  back;  if  the  sides  of  the  drift  are  uneven,  or  the  miners  misjudge 
the  distance  from  the  face  a  few  inches.  This  results  in  shortening  the  length 
of  the  hole  that  can  be  cut  with  any  one  drill.  Holes  shortened  four  inches, 
make  a  loss  of  7%  on  the  time  spent  in  rigging,  blasting,  changing  drills,  etc., 
which  operations  consume  approximately  50%  of  the  miner's  time,  making  a 
net  loss  of  3  1/2%  on  the  total  work  on  the  cut.  This  case  is  especially 
marked  with  drill  machines  having  too  short  a  feed  screw,  as  many  of  them 
have. 

The  face  of  the  drift  is  usually  uneven,  and  the  horizontal  bar  has  to  be 
rigged  far  enough  back  to  allow  room  for  a  " starter"  on  the  farthest  projecting 
surface.  Holes  drilled  at  an  angle  from  a  horizontal  bar,  such  as  cutting-in 
holes,  will  not  penetrate  so  far  in  the  line  of  the  drift  as  the  other  holes,  making 
an  uneven  space  when  the  round  is  blasted.  Of  course,  this  can  be  corrected  by 
shortening  the  straight  hole,  or  by  using  an  extra  drill  on  the  angle  holes,  but 
both  of  these  operations  mean  a  loss  of  time.  In  general,  a  cut  drilled  from  a 
single-screw  column  will  be  shorter  than  one  drilled  from  a  double-screw 
column,  so  that  the  time  sepnt  in  rigging,  changing  drills  and  blasting  is  not 
utilized  to  the  best  advantage. 

It  is  always  necessary  to  rig  the  horizontal  bar  twice,  the  second  occasion 
being  for  the  purpose  of  drilling  the  bottom  holes.  This  consumes  from  10  to 
30  minutes.  With  the  double-screw  column  it  is  often  possible  to  drill  an  entire 
cut  from  one  rigging. 

The  rigging  of  the  double-screw  column  vertically  is  usually  accomplished 
in  less  time  than  is  required  to  rig  a  single-screw  bar  horizontally,  especially 
where  much  blocking  has  to  be  done,  because  the  blocks  that  rest  on  the  top 
will  slide  out  from  between  the  single-screw  bar  and  the  side  of  the  drift.  Such 
details  may  affect  the  day's  work  of  a  single  miner  but  a  small  amount  per 
day,  but  the  aggregate  difference  in  work  done  by  a  force  of  men  in  a  year  is 
large. 

Bundling  Drill  Steel. — At  the  Hamilton  shaft  of  the  Chapin  mine,  where 
a  small  number  of  men  are  at  work  as  contract  miners,  the  steel  is  delivered 
at  the  surface  from  the  shop.  As  the  miners  come  out  for  their  dinner,  each 
drill  gang  selects  its  drills  for  the  next  shift.  These  are  all  bundled  together 
and  tied  with  a  wire.  While  the  men  are  out  at  noon,  the  steel  is  lowered 
and  sent  to  a  common  distributing  center  near  where  the  men  are  working. 


62  HANDBOOK  OF  MINING  DETAILS 

The  majority  of  the  work  is  by  contract,  and  each  contractor's  tools  are 
numbered.  This  saves  the  trouble  of  sorting  the  steel  underground  where 
the  light  is  usually  none  too  good.  It  also  facilitates  the  distribution  of  the 
steel.  The  steel  is  furnished  by  the  company  while  the  powder,  fuse  and  other 
tools  are  charged  directly  to  the  miner.  At  the  Ludington  shaft  where  most 
of  the  work  is  now  being  done,  one  man  is  employed  whose  only  work  is  to 
look  after,  collect,  and  deliver  the  drill  steel  to  the  miner. 

Handling  Drill  Steel  at  Champion  Mine. — The  best  way  of  handling  drill 
steel  at  a  mine  where  there  are  several  working  shafts  is  often  a  serious  question. 
There  are  several  places  at  some  mines  where  the  steel  is  sharpened  on  being 
brought  to  the  surface.  At  the  larger  mines  it  is  generally  better  to  sharpen 
the  steel  at  some  central  place.  The  reason  that  the  smaller  mines  favor  the 
sharpening  of  the  steel  at  each  shaft  is  that  the  cost  of  gathering  the  steel  is 
great  unless  the  quantity  is  large. 

This  problem  of  gathering  and  handling  the  steel  has  been  solved  in  a 
simple  manner  at  the  Champion  mine  of  the  Copper  Range  company  in 
Michigan.  At  this  mine  there  are  four  working  shafts  from  each  of  which 
steel  is  gathered.  Shaft  B  sends  up  about  325  drills,  shaft  C  250,  shaft  D  200, 
and  shaft  E  180  drills  per  day.  The  drills  are  sent  up  loose  on  the  cages,  and 
at  the  surface  are  loaded  directly  into  tank-steel  boxes  that  are  carried  in  the 
bed  of  a  wagon  in  summer  or  sleigh  in  winter.  These  boxes  are  made  in  three 
pieces,  a  bottom  and  two  hinged  sides  to  which  rings  are  fastened  for  receiving 
the  hoops  of  the  chains  used  to  lift  the  boxes  out  of  the  wagon.  While  in 
the  wagon  the  sides  of  the  boxes  are  held  up  by  the  sides  of  the  wagon  or 
sleigh. 

In  loading  these  drills  they  are  sorted  according  to  size  so  that  they  can  be 
sharpened  at  the  shop  without  any  needless  increase  in  the  handling.  Each 
shaft  has  its  own  wagon  or  sleigh.  When  it  has  been  loaded  with  dull  drills 
the  team  which  does  the  hauling  for  the  shafts  comes  for  the  wagon  in  the 
morning  and  hauls  it  to  the  blacksmith-shop  with  its  load  of  drills.  While 
the  team  goes  after  another  load  from  another  shaft,  the  drills  are  unloaded 
by  means  of  an  air  lift  .attached  to  a  trolley  that  travels  on  an  I-beam  carried 
in  the  frame  of  the  shop. 

Picking  the  boxes  up  with  their  load  of  drills  at  A,  in  Fig.  30  by  hooking 
chains  into  the  rings  on  their  sides,  the  2  i/ 2-ton  air-lift  B  traveling  on  the 
overhead  trolley  takes  its  load  to  rack  C  in  back  of  the  heating  furnace  and 
on  the  same  side  as  the  drill  sharpener  so  that  the  drills  can  be  readily  placed 
in  the  furnace.  There  the  chains  are  unhooked  from  the  box  and  the  sides 
allowed  to  fall  flat  on  the  drill  rack  C.  When  all  of  the  drills  have  been  taken 
from  the  box  during  the  progress  of  sharpening,  the  box  is  lifted  with  the 
air  lift  and  taken  over  to  rack  D  where  it  is  put  down  between  some  pegs  that 
will  hold  up  its  sides. 

As  fast  as  the  drills  are  sharpened  they  are  sent  over  to  the  other  side  of 


ROCK  DRILLS  63 

the  heating  furnace  to  be  tempered.  On  the  tempering  side  is  a  cooling  rack 
where  the  drills  are  held  for  the  proper  color  to  come  and  then  are  plunged  into 
the  cooling  tank  which  is  at  the  side  of  rack  D.  From  the  cooling  tanks  the 
drills  are  put  in  the  boxes  resting  on  rack  D,  being  placed  in  the  boxes  of  the 
mine  to  which  the  drills  belong.  As  soon  as  all  the  drills  for  one  shaft  have 


Drill  Sharpening 

Machine  Tempering  Trough 


FIG.   30. — DRILL   SHARPENING   PLANT  AT  CHAMPION  MINE. 

been  tempered,  the  boxes  are  picked  up  by  the  traveling  air  lift,  taken  back 
and  loaded  into  the  wagon  that  is  standing  under  the  loading  place.  Then  the 
drills  are  hauled  back  to  the  shaft,  where  the  boys  sort  out  the  drills  belonging  to 
each  machine  by  the  numbers  that  are  cut  in  their  shanks  and  load  them  on  the 
cage,  those  for  one  machine  pointing  up,  those  for  the  next  machine  on  that  level 
down,  thus  each  machine  gets  back  as  many  drills  as  were  sent  up. 

In  this  way  the  handling  of  the  drills  is  reduced  to  a  minimum,  and  yet  all  the 


64  HANDBOOK  OF  MINING  DETAILS 

advantages  of  central  sharpening  are  retained  for  scattered  shafts.  The  only 
investment  other  than  would  be  required  ordinarily  is  the  providing  of  a  wagon 
costing  $50  or  $60  to  serve  each  shaft.  The  hauling  is  done  by  one  of  the  teams 
that  is  maintained  to  do  general  hauling  about  the  mine.  This  system  of  hand- 
ling the  steel  has  been  in  use  for  a  long  time  at  the  Champion  mine  and  is 
satisfactory. 

Mine  Dust  Prevention  on  the  Rand  (By  E.  M.  Weston). — There  are  two 
types  of  dust  arresters  in  use  on  the  Rand,  one  being  merely  an  arrangement 
to  trap  the  dust  in  a  wet  sack  and  the  other  adopting  the  old  suction  principle. 
That  designed  by  Doctor  Aymard  belongs  to  the  first  class  and  the  other  is 
known  as  Pursers'.  The  government,  the  mine  owners  and  to  a  certain  extent 
the  miners  have  begun  to  realize  the  terrible  loss  to  the  community  and  to  the 
industry  in  the  destruction  of  the  skilled-laborer  supply  and  the  life,  moral 
nature  and  efficiency  of  the  miners  that  is  caused  by  unhealthy  conditions  in 
mining.  Of  these  the  worst  effects  as  regards  health  have  been  caused  by  the 
gases  produced  by  explosives  and  more  particularly  by  the  dust  produced  by 
blasting,  by  rock  drilling  in  upper  holes  and  by  shoveling. 

With  regard  to  dust  from  drilling  uppers  with  either  piston  or  hammer 
drills,  most  miners  refuse  to  use  a  water  jet  to  kill  the  dust  in  the  hole,  but 
lately  I  have  met  a  few  miners  here  who  are  using  water  jets  in  raises.  The 
general  complaint  is  that  owing  to  the  splash  and  drip,  it  is  pleasanter  to  die 
of  phthisis  than  of  rheumatism.  Sprays  affixed  to  the  machine  have  never  been 
popular  here,  as  they  increase  the  humidity  of  the  air  greatly  and  do  not  lay 
more  than  70%  of  the  dust.  Leyner  drills  or  any  hammer  drills  working 
with  hollow  steel  are  not  in  use,  though  I  think  the  improved  Leyner  drill  using 
hollow  steel  bits  in  one  piece  may  yet  find  a  place  here  for  certain  work.  When 
a  fair  sized  mine  like  the  Nourse  blunts  27,000  drill  bits  a  week  the  question 
of  maintenance  of  hollow  steel  is  a  serious  one.  I  can  say  that  at  present  there 
is  no  serious  attempt  being  made  on  this  field  to  destroy  the  dust  in  the  hole 
itself  when  boring  dry  holes. 

Many  attempts  have  been  made  to  design  an  apparatus  that  will  collect  all 
the  dangerous  dust  at  the  mouth  of  the  hole.  Mr.  Remeaux  of  France  has 
recently  done  some  work  on  the  subject.  It  is  comparatively  easy  to  design  a 
device  that  will  collect  the  dust,  but  the  trouble  is  to  design  something  that  will 
not  detract  from  the  efficiency  of  the  work  and  will  not  hinder  the  men,  or  take 
too  long  to  adjust.  Pursers'  dust  arrester,  shown  in  Fig.  31,  consists  of  a 
short  length  of  piping  of  such  a  size  at  one  end  and  perhaps  split  so  that  it  can 
be  driven  into  the  mouth  of  the  hole  formed  by  the  starter  drill  bit.  To  the 
outer  end  is  fixed  a  T-piece  with  the  opening  pointing  downward  and  to  this 
opening  is  fixed  a  reducing  piece  and  an  air  cock  and  small  air  jet  to  act  as  an 
injector  and  on  the  end  is  a  wet  bag  or  a  pipe  opening  under  water.  The  idea 
being  that  after  the  hole  is  started  the  pipe  is  driven  in  and  the  air  connection 
made  and  the  suction  of  air  will  draw  in  the  dust.  There  are  several  disadvan- 


ROCK  DRILLS  65 

tages  connected  with  this  device:  (i)  It  involves  the  use  of  a  certain  amount 
of  air  and,  as  the  ordinary  3/4-in.  hose  in  use  does  not  supply  a  3  i/4-in.  drill 
with  sufficient  air  as  it  is,  it  thus  hinders  drilling.  (2)  It  could  not  be  used  in 
a  steep  hole  as  the  dust  would  fall  past  the  opening.  (3)  It  involves  the  use 


FIG.  31. — PURSERS'  DUST  ARRESTER. 

of  an  air  hose  about  the  feet  of  the  drill  tender,  a  "spanner  boy,"  where  it  is 
sure  to  get  damaged  or  to  be  in  the  way  in  removing  drills  from  the  chuck. 

The  construction  of  Doctor  Aymard's  device  and  its  use  with  hammer  and 
piston  drills  is  shown  in  Fig.  32.  A  conical  ring,  which  can  be  made  by  riveting 
sheet  iron  (or  better  by  a  drop  forging  out  of  a  piece  of  weldless  tubing)  is  hung 
by  two  trunnions  in  the  yoke  of  wrought  iron  which  is  connected  with  a  bar 


FIG.  32. — AYMARD'S  DUST  COLLECTOR. 

sliding  in  a  tube  which  can  be  clamped  in  any  position  by  the  set  screw  shown. 
Over  this  ring  is  sewn  a  bag  of  jute  sacking  of  the  shape  shown  and  with  a 
piston  drill  the  other  end  of  the  sack  is  supported  by  a  loose  ring  which  slides 
on  the  drill  bit.  With  a  hammer  drill  the  bottom  of  the  bag  is  tied  round  the 
5 


66  HANDBOOK  OF  MINING  DETAILS 

drill  steel.  This  apparatus  requires  some  small  trouble  in  fixing,  but  I  believe 
it  to  be  a  practical  device  that  might  be  adopted  in  many  American  mines  with 
advantage  where  the  hammer  drill  has  already  earned  the  unenviable  name  of 
"widow  maker."  The  miner  if  he  wishes  to,  can  make  a  good  use  of  this 
device  which  costs  only  £  i  to  make,  and  it  will  pay  miners  to  install  it.  The 
sacking  is,  of  course,  kept  damp  to  settle  and  collect  the  dust.  I  have  heard 
it  said  that  the  bag  is  liable  to  catch  the  chuck  of  the  machine  but  this  is  easily 
guarded  against  with  care.  On  the  mines  of  the  Rand,  the  only  real  objection 
to  the  .use  of  dust  arresters  with  piston  drills  is  that  where  three  drills  are 
employed  in  one  face,  there  is  no  room  for  their  use;  but  on  one  of  the  large 
mines  the  other  day  quite  a  number  of  these  devices  were  shown  that  had 
been  wilfully  damaged  by  the  miners  to  avoid  using  them.  The  new  miners' 
phthisis  compensation  act  will  have  one  good  result  as  it  makes  it  in  the  interest 
of  the  mine  owners  to  secure  as  many  convictions  as  possible  against  their 
workmen  for  breaches  of  the  act,  as  three  convictions  render  a  miner  ineligible 
for  compensation. 

The  Dwyer  Dust  Arrester. — The  Dwyer  dust  arrester  is  intended  for  use 
with  rock-drilling  machines  that  can  be  so  operated  that  the  exhaust  air  will 
pass  down  the  tubular  steel  bit  to  the  bottom  of  the  hole  being  drilled,  to  blow 
the  dust  and  cuttings  made  by  the  bit  through  the  annular  space  between  the 
bit  and  walls  of  the  hole.  The  device  is  a  receptacle  that  permits  escape  of 
the  air,  but  retains  the  cuttings.  In  the  accompanying  illustration  of  the  device, 


FIG.    33. — DWYER   DUST-COLLECTING    DEVICE. 

Fig.  33,  A  is  a  sheet  of  metal  rolled  into  a  cylinder,  the  edges  of  which  are  free 
to  overlap  as  much  as  may  be  necessary  to  introduce  it  into  the  mouth  of  the 
hole  cut  to  sufficient  depth  by  a  starting  bit,  to  permit  introduction  of  the  collar 
far  enough  into  the  hole  to  obtain  a  tight  fit.  To  the  collar  is  tied  a  bag  B, 
which  has  an  opening  at  C  for  slipping  over  the  collar.  The  bag  is  attached  to 
the  collar  by  an  elastic  band.  At  D  there  is  an  opening  in  the  bag  through 
which  the  drill  passes.  To  the  neck  of  the  bag  at  the  point  D  is  attached  a  cord 
carrying  a  weight  at  the  end.  This  cord  is  wrapped  about  the  neck  of  the  bag 
to  hold  it  to  the  drill ;  the  weight  making  tying  unnecessary.  The  bag  B  may 
be  made  of  some  light  open  fabric  through  which  the  air  will  pass,  but  which 
will  filter  the  dust,  or  heavy  material,  such  as  leather,  may  be  used,  in  which 
case  a  large  opening  E  is  made  in  the  bag  in  which  a  sponge  is  held,  through 


ROCK  DRILLS 


67 


which  the  air  escapes  while  the  dust  is  retained.     The  device  was  invented  by 
William  E.  Dwyer,  of  Leadville,  Colo.,  and  is  patented. 

Water  Blast  for  Allaying  Dust.— The  James  water  blast,  illustrated  in 
Fig.  34,  was  developed  in  South  Africa  and  now  is  used  in  many  of  the  mines 
on  the  Rand.  In  a  recent  report  by  the  Royal  Commission  on  Mines  on  New 
Zealand,  this  type  of  dust  allayer  was  recommended  for  adoption  in  the  mines 
of  that  country.  The  blast  is  intended  especially  for  allaying  dust  and  absorbing 
noxious  powder  fumes  immediately  after  blasting.  As  shown  in  Fig.  34,  the 
appliance  is  simple,  consisting  of  a  short  piece  of  6-in.  pipe  about  10  ft.  long 
closed  at  each  end  by  a  flange  which  has  been  tapped  and  threaded  so  that  the 
6-in.  pipe  can  be  installed  in  any  part  of  the  2-in.  compressed-air  mains.  When 


FIG.    34. — WATER   BLAST  AND   DRAFT   INDUCER   FOR  ALLAYING   DUST   IN   DRIFTS. 


placed  in  position  the  side  of  the  6-in.  pipe  is  tapped  and  threaded  for  a  small 
pipe  by  which  connection  is  made  with  a  supply  of  water  under  low  pressure. 
This  may  be  obtained  conveniently  by  providing  a  tank  or  cistern  for  water 
storage  in  some  part  of  the  mine  above  the  level  in  which  the  water  blast  is 
used.  Valves  in  the  2-in.  service  pipe  and  in  the  small  water  supply  pipe  are 
used  to  control  the  flow  of  air  and  water.  While  drilling  is  going  on  the  air 
valve  is  left  wide  open,  but  the  water  valve  is  closed.  When  ready  to  blast 
the  miners  close  the  air  valve  and  open  the  water  valve;  the  6-in.  cylinder  is 
quickly  rilled  with  water.  As  soon  as  the  blast  has  been  fired  the  air  valve  is 
opened  suddenly  causing  the  water  contained  in  the  6-in.  pipe  to  be  ejected 
into  the  face  of  the  drift  in  the  form  of  a  fine  spray.  The  spray  of  water  is 
effective  for  a  distance  of  30  or  40  ft.  back  from  the  face.  To  promote  further 
ventilation  an  induction  draft  pipe  as  shown  in  the  sketch  may  be  used  to 
deliver  air  at  the  face  or  to  withdraw  air  from  it.  The  water  blast  not  only 
allays  the  dust  made  while  blasting,  but  wets  the  broken  material  so  thoroughly 
that  little  or  no  dust  is  raised  by  shoveling. 


IV 
SHAFT  WORK 

Methods  in  Use— Timbering— Use  of  Steel  and  Concrete— Shaft 
Stations  and  Skip  Pockets 

Shaft  Sinking  at  the  Pioneer  Mine.— The  vertical  shaft  of  the  Pioneer 
mine,  Ely,  Minn.,  is  being  sunk  200  ft.  from  the  i4oo-ft.  level.  Fig.  35  shows 
the  method  followed  in  this  work.  The  sinking  had  to  be  done  without  inter- 
fering with  the  hoisting  of  ore.  A  station  about  25X60  ft.  was  cut  on  the 


~T~ 

4. 

-J-l  1  1  fv  ]  1  i  1  1  1  1 
Hoist 

,/>             Ran 

4-1  H 

HH|£H 

FIG.    35. — SHAFT   SINKING   UNDER    ROCK   PENTICE,    PIONEER   MINE. 

i4oo-ft.  level  and  an  inclined  winze  started  near  the  center  of  the  station.  This 
winze  was  extended  on  about  a  45°  slope  until  it  intersected  the  line  of  the 
main  shaft  leaving  a  rock  pentice  in  the  bottom  of  the  shaft  just  above  where 
the  new  work  was  to  begin.  After  the  completion  of  the  winze  a  i-in.  cable 
was  anchored  in  the  roof  of  the  station  and  in  the  side  of  the  shaft  extension, 

68 


SHAFT  WORK  69 

as  shown.  This  cable  was  used  as  a  track  upon  which  a  carrier  was  operated. 
A  small  hoist  was  placed  near  the  farther  end  of  the  station,  and  a  i-ton  bucket 
was  used  for  handling  the  broken  rock.  The  bucket  is  drawn  up  by  a  3/4-in. 
cable  until  the  bail  strikes  the  carrier  on  the  stationary  cable.  The  carrier 
then  conveys  the  bucket  to  the  station  where  it  is  emptied  into  a  car  and 
trammed  by  hand  to  the  shaft  and  hoisted  on  the  man  and  timber  cage,  thus 
not  interfering  with  the  hoisting  of  the  ore.  The  shaft  is  7  1/2X24  ft.  and 
has  four  compartments. 

Rapid  Shaft  Sinking  in  Butte  (By  C.  J.  Stone).— The  following  notes 
concern  more  particularly  the  equipment  and  the  methods  employed  in  sinking 
the  shaft  of  the  Butte- Alex  Scott  Copper  Co.  below  the  i4oo-ft.  level,  rather 
than  any  general  description  of  methods  in  the  Butte  district.  During  April, 
1910,  an  effort  was  made  to  attain  the  greatest  possible  speed  at  shaft  sinking, 
consistent  with  good  work  and  safety  to  the  miners,  and  as  a  result  106  ft. 
was  sunk  from  the  i4oo-ft.  level  in  30  working  days. 

The  shaft  has  but  two  compartments,  each  being  4  ft.  square  in  the  clear. 
The  rock  was  all  hoisted  to  the  surface  in  straight-sided  buckets  27  in.  in 
diameter  by  42  in.  deep,  swung  from  the  bottom  of  a  skeleton  sinking  cage  of 
light  construction.  The  sinking  cage  measures  16  ft.  from  its  bottom  to  the 
top  of  the  sinking  shoes.  A  previous  sinking  campaign  had  developed  serious 
trouble  from  the  loaded  bucket  swinging  and  striking  the  wall  plates  of  the 
shaft  at  times  when  rapid  hoisting  was  necessary.  To  eliminate  this  the  bucket 
is  hung  from  two  chains  close  to  the  bottom  of  the  cage,  only  sufficient  space 
being  allowed  to  permit  its  being  detached  while  at  the  bottom  of  the  shaft. 
A  ring  is  welded  into  the  bucket  at  each  side  and  a  finger  hook,  such  as  is  used 
on  logging  chains,  is  passed  through  the  ring  and  locked  in  place  by  a  slip 
ring.  A  screw-eye  fastens  the  chain  to  the  cage  and  furnishes  the  adjustment. 
With  this  device  an  adjustment  can  be  secured  on  the  chains  that  will  permit 
only  the  least  amount  of  swinging  of  the  bucket  in  the  shaft,  and  hoisting  can 
be  done  at  any  speed  desired  and  with  perfect  safety  to  the  miners  below. 
The  chains  may  be  quickly  detached  to  remove  the  bucket. 

The  working  crew  consists  of  four  machine  miners  and  one  pump  man  on 
each  shift,  and  three  eight  hour  shifts  constitute  the  day.  One  of  the  miners 
on  each  shift  acts  as  a  working  boss  and  he  is  paid  75  cents  extra  per  shift.  Two 
3  i/8-in.  Ingersoll-Rand  drills  are  used  under  an  air  pressure  of  85  to  90  Ib. 
at  the  compressor.  The  cut  holes  are  drilled  from  8  to  9  ft.  deep  and  a  wedge 
bit  is  used  on  the  finishing  drill.  The  side  or  back  holes  are  6  ft.  deep.  It 
requires  from  1 6  to  19  holes  to  break  the  ground,  which  is  for  the  most  part  a 
hard  granite  with  the  partings  or  cleavages  running  the  long  way  of  the  shaft. 
The  blasting  is  rarely  perfectly  satisfactory.  Should  the  ground  be  particularly 
soft  and  the  cleavages  favcrable,  a  blast  will  probably  break  to  the  bottom  of  the 
holes.  Under  ordinary  circumstances,  however,  from  18  in.  to  2  ft.  will  have 
to  be  fired  again. 


70  HANDBOOK  OF  MINING  DETAILS 

The  practice  in  some  large  shafts  is  to  blast  the  cut  holes  first  and  after 
mucking,  blast  their  bottoms  until  the  cut  is  entirely  out,  when  the  remainder  of 
the  holes  are  fired.  Experience  has  shown  that  better  results  are  obtained  if  the 
cut  holes  are  fired  with  a  battery,  but  the  damage  to  the  timbers  when  sinking  in 
hard  rock  is  so  great  that  the  method  has  not  found  favor  in  Butte  and  the 
old  method  of  blasting  with  waterproof  fuse  maintains.  Forty  per  cent,  gelatin 
dynamite  is  used. 

The  water  is  handled  with  a  No.  7  Cameron  sinking  pump.  The  air 
exhaust  is  passed  through  a  check  valve  into  the  water  or  discharge  column.  This 
eliminates  the  roar  of  the  exhaust  in  the  shaft  and  makes  it  possible  for 
either  a  Knowles  or  a  Cameron  sinker  to  lift  water  200  ft.  in  place  of  100  ft., 
which  is  the  .normal  lift  of  a  No.  7  pump.  In  the  sinking  of  the  Alex  Scott 
shaft  the  flow  of  water  varied  from  20  to  30  gallons  per  minute  and  no  time 
was  lost  during  the  month  because  of  water  in  the  shaft. 

The  hoisting  was  done  as  rapidly  as  possible.  During  the  mucking  hours 
the  bucket  was  brought  to  the  surface  from  the  i5oo-ft.  level  in  from  30  to  45 
seconds,  according  to  the  engineer.  The  hoisting  engine  is  of  the  first  motion 
type,  built  for  high  pressure;  the  cylinders  are  12X36  in.  and  the  drum  is  5 
ft.  in  diameter.  It  was  built  by  the  Nordberg  Manufacturing  Company. 

The  timbering  is  the  usual  shaft  set.  The  sets  are  of  ioX  lo-in.  black 
larch  and  fir  timber,  placed  5  ft.  between  centers  and  lagged  with  2X10-  or 
3Xn-in.  plank.  Each  set  is  thoroughly  blocked  and  wedged  and  absolutely 
no  cutting  is  allowed.  The  shaft  must  be  broken  sufficiently  large  to  hang  the 
sets  free  from  the  walls  and  the  lagging  must  be  placed  loose  to  permit  later 
swelling  of  the  ground.  For  blasting  timbers  heavy  channel  irons  are  used, 
the  channels  being  bolted  tight  to  the  bottom  set  before  firing.  Openings  are 
cut  in  the  channels  for  the  nuts  of  the  hanging  bolts.  The  ends  and  the  centers 
are  protected  in  this  way  as  well  as  the  wall  plates.  A  marked  difference  is 
noted  in  the  physical  condition  of  the  timbers  by  the  use  of  the  channel  irons  in 
place  of  the  ordinary  5X  10  blasting  timbers. 

The  bonus  or  premium  system  was  employed  as  one  means  of  securing 
rapid  work.  The  ordinary  speed  of  shaft  sinking  below  the  i2oo-ft.  level  in 
Butte  is  from  65  to  85  ft.  per  month.  As  a  basis  for  the  bonus,  therefore,  75  ft. 
were  taken  and  the  shaft  miners  and  pump  men  were  given  each  one  dollar  per 
foot  for  every  foot  that  was  accomplished  above  the  base  during  the  month. 
In  this  instance  it  amounted  to  $31  bonus  to  each  man  as  a  reward  of  merit. 
The  bonus  cost  per  foot  amounted  to  $15,  and  the  entire  or  actual  labor  cost 
for  the  106  ft.  accomplished,  including  the  bonus,  amounted  to  $36.54  per  foot. 
Should  only  ordinary  speed  have  been  made  and  the  bonus  system  not  employed 
as  an  incentive  for  hard  and  faithful  labor,  the  cost  would  have  been  $45.46 
per  foot.  However,  as  the  actual  amount  of  sinking  that  otherwise  might 
have  been  accomplished  is  an  unknown  factor,  the  latter  figure  is  only  an  assump- 
tion on  the  base  or  average  measurement. 


SHAFT  WORK  71 

Shaft  Sinking  at  Stella  Mine,  New  York.— The  drawings  in  Figs.  36 
and  37  show  the  methods  of  shaft  sinking  used  by  the  St.  Lawrence  Pyrites  Co., 
DeKalb  Junction,  N.  Y.  In  each  case  it  was  desired  to  sink  the  shaft  and 
at  the  same  time  continue  hoisting  ore.  As  there  were  no  levels  below  the  shaft 
sump,  there  was  no  opportunity  for  extending  the  shaft  by  means  of  a  raise 
from  lower  levels.  The  Stella  shaft  is  inclined  at  an  angle  of  18°;  the  Anna 
at  45° 

At  the  Anna  shaft  advantage  was  taken  of  an  existing  crosscut,  and  a  stope 
in  an  upper  branch  to  start  the  new  section  of  the  shaft,  back  of  and  above 


Electric 

Hoist 


FIG.    36. — DETAILS    OF  ANNA   SHAFT   EXTENSION. 

the  sump.  The  hanging  wall  was  taken  out  sufficiently  to  allow  the  construction 
of  a  small  ore  bin,  as  shown  in  Fig.  36,  and  at  the  same  time  provide  space  for 
the  sheave.  An  electric  hoist  was  installed  in  the  crosscut  a  little  to  one  side 
of  the  shaft.  The  ore  bin  is  constructed  just  above  the  incline  shaft  so  that  the 
ore  can  be  dumped  directly  into  the  skip  and  taken  to  the  surface.  A  small  self- 
dumping  skip  is  used  in  the  shaft  extension  and  all  the  material  from  the  shaft 
is  dumped  into  the  ore  bin. 


72 


HANDBOOK  OF  MINING  DETAILS 


The  method  employed  at  the  Stella  shaft  is  to  drift  out  about  20  or  25  ft. 
from  one  side  of  the  main  shaft  and  then  sink  on  the  incline  at  such  an  angle 
as  to  meet  the  line  of  the  permanent  shaft  at  a  distance  of  30  to  35  ft.  below  the 
working  level.  One  reason  for  not  cutting  out  the  hanging  wall,  as  was  done 
at  the  Anna,  was  that  the  roof  was  barren.  In  the  Stella,  all  of  the  work  was 
done  in  the  main  orebody.  When  the  line  of  the  main  shaft  was  reached,  this 
auxiliary  shaft  was  then  deflected  to  as  to  be  a  continuation  of  the  desired  shaft. 
The  ore  from  the  auxiliary  shaft  is  dumped  into  the  bin  and  transferred  by  car 
to  the  main  shaft.  Another  advantage  of  sinking  the  shafts  by  these  methods 
is  that  the  sump  is  maintained  in  perfect  condition  and  the  pumps  are  able  to 
take  care  of  all  of  the  water  so  that  the  work  below  was  comparatively  dry. 


Electric  Hoist 


Main  Shaft,  ?0  Slop*. 

FIG.    37. — PLAN    OF   STELLA   SHAFT. 

Bucket  Trolley  for  Shaft  Sinking  (By  L.  E.  Ives).—  The  problem  of 
maintaining  a  normal  production  of  ore  from  a  shaft  in  which  sinking  is  being 
carried  on,  is  one  that  constantly  confronts  the  mine  superintendent.  In  Fig. 
38  is  illustrated  a  method  used  in  the  Michigan  copper  country,  at  a  number 
of  important  mines. 

The  sketch  shows  a  section  of  an  inclined  shaft,  but  does  not  show  details 
of  timbering.  A  and  B  represent  the  two  bottom  plats  from  which  ore  is  being 
mined  and  hoisted.  Below  the  bottom  plat  B,  and  not  indicated  in  the  sketch, 
is  a  pentice,  or  bulkhead,  which  prevents  the  skip,  in  case  of  accident,  from 
descending  upon  the  miners  who  are  engaged  in  sinking  at  the  working  face  M. 
While  affording  protection  to  the  miners,  the  pentice  at  the  same  time  precludes 
the  possibility  of  loading  the  muck  from  the  working  face,  directly  into  the  skip. 
Again,  even  were  this  possible,  it  is  undesirable  for  the  reason  that  the  skip  would 
be  taken  out  of  ore-hoisting  service  for  too  long  periods. 

The  pentice  is  extended  across  both  skip  compartments,  but  terminates  just 
short  of  the  ladderway.  Over  the  center  of  the  ladderway,  and  at  the  proper 
spacing,  holes  are  drilled  in  the  hanging  wall  into  which  iron  eye-pins  N  are 
inserted  and  wedged.  From  these  eye-pins,  by  means  of  chains  G,  is  supported 
an  I-beam  F  in  such  a  way  that  the  flat  side  of  the  flange  is  parallel  to  the 
hanging  wall  and  about  10  in.  or  a  foot  from  it.  Along  this  I-beam  runs  the 


SHAFT  WORK 


73 


trolley  K.  The  latter  is  triangular  in  form,  but  the  angles  vary  with  the  dip 
of  the  shaft  in  which  it  is  used.  It  is  so  constructed  that  when  the  trolley  and 
bucket  are  being  hoisted,  or  in  other  words,  when  the  trolley  is  running  along 
the  I-beam,  the  bucket  is  suspended  vertically  beneath  the  pulley,  which  is 
farthest  up  the  shaft  along  the  I-beam.  Only  one  rope  E  is  used  and  in  lowering 
the  bucket  L,  when  the  trolley  is  stopped  by  a  projection,  placed  for  the  purpose 
at  the  lower  end  of  the  I-beam,  the  rope  continues  to  lower  the  bucket  to  the 
working  bottom,  as  indicated  by  the  dotted  lines.  Here  the  rope  is  unhooked 
from  the  bucket,  if  desired,  and  the  latter  may  be  moved  to  any  part  of  the 


FIG.   38. — BUCKET   TROLLEY   FOR   SHAFT   SINKING. 

bottom.  In  hoisting,  when  the  bucket  reaches  the  trolley,  the  former  auto- 
matically clamps  into  the  latter  and  with  no  delay  whatever,  trolley  and  bucket 
together  continue  to  move  upward,  until  the  point  for  dumping  is  reached. 

In  dumping  and  loading  into  the  skip  two  methods  are  in  use.  In  either  case 
the  bucket  is  dumped  into  a  chute.  In  one  case,  however,  the  contents  run 
immediately  into  a  tram  car  and  this,  when  filled,  is  pushed  around  and  dumped 
into  the  skip,  just  as  ore  would  be.  In  the  other  case,  and  this  is  used  pref- 
erably where  only  one  compartment  is  being  used  for  hoisting  ore,  the  bucket 
is  dumped  into  a  bin  which  is  built  in  the  unused  compartment.  The  mouth 
of  this  bin  is  so  placed  that  when  the  latter  is  full  and  a  skip  is  available,  the 
gate  is  opened  and  the  entire  contents  of  the  bin  are  dumped  at  once  into  the 
waiting  skip.  For  hoisting  the  bucket  and  trolley  an  ordinary  wire  rope  is 
used  and  a  compressed-air  hoist  H,  usually  called  a  puffer,  is  placed  on  a 
platform,  built  at  a  point  between  the  two  deepest  levels.  The  hoist  is  operated 
easily  by  a  boy.  C  D  indicates  the  top  of  the  skip  rail. 

A  Two-way  Shaft. — We  once  observed  in  Colorado  a  unique  method  of 
prospecting  a  vein,  which  is  not  to  be  generally  recommended,  but  in  this 
case  well  served  its  purpose,  and  conformed  to  the  cardinal  principle  of  pros- 
pecting, namely,  " Follow  the  ore."  A  vertical  shaft  had  been  started  on 
vein  outcropping  at  A.  About  50  ft.  down,  at  B,  the  vein  was  found  to  split. 
The  chances  seemed  to  be  that  it  was  going  around  a  horse,  the  latter  appearing 


74 


HANDBOOK  OF  MINING  DETAILS 


to  be  of  large  size,  and  both  branches  of  the  vein  looking  equally  good.  In  order 
to  follow  them  both,  the  vertical  shaft  was  converted  into  a  two-way  shaft  as 
shown  in  Fig.  39.  Hoisting  was  done  regularly  from  both  branches.  Skids 
were  laid  in  branches  B  C  and  B  D,  the  buckets  sliding  down  and  being  dragged 
up  upon  them.  The  upper  end  of  the  skids  were  extended  by  a  movable  switch, 
constructed  of  two  pieces  of  timber,  pivoted  at  the  lower  end.  In  hoisting  from 
B  C,  the  switch  was  thrown  in  the  position  Z  Y.  When  it  was  desired  to  hoist 
from  B  D,  the  switch  was  thrown  over  to  X  Z  causing  the  bucket  to  descend  in 
the  desired  direction.  Of  course,  it  was  necessary  to  place  rollers  for  the 
cable  at  X  and  Y,  which  are  shown  in  the  sketch  in  an  exaggerated  form,  in 
order  to  make  the  arrangement  quite  clear. 


FIG.    39. — AN   UNUSUAL   TWO-WAY    SHAFT. 

Securing  Loose  Rock  by  Bolts.— In  the  Camp  Bird  mine  the  wall  rock  is 
quite  hard  and  in  most  cases  stands  well,  but  in  the  driving  of  the  main  raise 
extending  from  the  haulage  level  to  the  upper  workings,  through  which  supplies 
and  men  are  hoisted,  several  large  slabs  of  rock  began  to  loosen  after  the  timber- 
ing of  the  raise  was  well  under  way.  Cracks  began  to  open  behind  these  slabs 
which  would  have  come  down  in  pieces  weighing  several  tons  had  is  been  neces- 
sary to  blast  them.  As  this  could  not  be  done  without  considerable  danger  to  the 
timber  in  the  raise,  the  slabs  were  bolted  in  place  in  the  following  manner:  A 
slab  was  securely  spragged  in  place  by  temporary  stulls  running  across  the  raise, 
so  that  is  could  not  move  or  at  least  without  giving  ample  warning.  Single- 
jack  holes  were  drilled  through  the  slabs,  which  were  themselves  quite  solid, 
and  into  the  solid  ground  behind  them  for  a  distance  of  a  foot  or  more.  Then 


SHAFT  WORK  75 

the  depth  of  the  hole  was  measured,  and  an  old  piece  of  drill  steel,  with  its  head 
well  upset  so  as  to  form  a  strong  head  like  that  of  a  bolt,  was  cut  off  to  the 
right  length  and  the  lower  end  split.  A  narrow  steel  wedge  was  then  inserted 
in  the  split  end,  which  was  pushed  into  the  hole,  wedge-end  first,  until  the  wedge 
was  against  the  bottom;  then,  by  hammering,  the  split  ends  of  the  drill  were 
spread  until  the  bolt  was  securely  anchored  in  the  wall  rock  behind  the  slab  of 
ground,  thus  holding  the  slab  tightly  in  place.  The  sprags  were  then  removed. 
These  slabs  had  been  held  by  bolts  7  or  8  years  when  my  attention  was  called 
to  them.  Apparently  they  had  not  moved  a  fraction  of  an  inch  since  they  were 
bolted  to  the  wall  behind  them.  Several  bolts  were  used  in  each  slab  placed 
according  to  the  direction  of  the  crack  behind  them.  The  method  of  securing 
the  bolts  in  the  wall  rock  is,  of  course,  the  same  as  that  of  anchoring  bolts  in 
concrete  when  for  any  reason  new  bolts  have  to  be  used  in  old  foundations. 

TIMBERING 

Necessity  of  Strong  Partitions  in  Shafts. — It  is  usual  and  proper,  in  a 
mine  shaft,  to  separate  the  compartment  reserved  for  the  men  from  those 
through  which  the  ore  is  hoisted  to  the  surface.  In  some  mines  it  appears  to  be 
considered  that  any  sort  of  timbering  is  good  enough  to  form  the  partition,  and 
it  would  seem  as  if  the  temptation  to  use  thin  planking  which  can  be  nailed 
in  place  almost  as  quickly  as  it  can  be  sawed,  is  almost  too  strong  to  be  resisted. 
In  one  such  case  an  accident  of  a  serious  nature  was  only  avoided  by  a  mere 
chance.  A  skip  was  being  hauled  to  the  surface,  containing  a  number  of  large 
pieces  of  ore.  It  had  been  nearly  filled,  and  by  some  means  the  top  piece  became 
dislodged  and  fell  over  the  skip  into  the  shaft.  In  falling  it  glanced  against 
the  timbering  of  the  partition,  then  went  down  the  shaft,  bounding  from  side 
to  side.  As,  however,  it  passed  down,  its  momentum  increased,  until  near  the 
bottom  of  the  shaft,  the  thin  wooden  partition  was  not  strong  enough  to  throw 
it  off  again,  and  it  crashed  through  the  timber  into  the  compartment  reserved 
for  the  men.  By  the  merest  chance,  no  one  was  there  at  the  time.  If  there 
had  been  a  workman  in  the  way,  he  would  most  assuredly  have  been  killed  as  the 
fall  was  a  long  one.  It  is  just  this  sort  of  thing  which  a  manager  of  a  mine 
should  foresee  and  prevent  as  far  as  possible  by  making  his  constructions  amply 
strong,  even  at  increased  expense. 

Corner  Framing  of  Shaft  Timbers  (By  W.  H.  Storms).— There  is  some 
diversity  in  the  style  of  framing  timbers  for  shafts.  The  difference  is  found 
chiefly  at  the  corners,  and  while  each  method  has  its  advocates,  any  of  these 
several  methods  will  answer  all  purposes  under  certain  conditions,  for  all  are  in 
practical  use.  The  drawings  shown  in  Fig.  40  illustrate  the  several  styles. 
Only  the  ends  of  the  wall  plates  are  shown,  it  being  understood  that  the  end 
plates  must  be  framed  in  exact  conformity  with  the  wall  plates.  In  each 
case  the  daps  in  which  the  posts  must  rest  are  either  shown  or  are  provided  for. 
In  Fig.  i,  the  dap  is  shown  on  both  upper  and  lower  sides;  in  Fig.  2  it  shows 


76 


HANDBOOK  OF  MINING  DETAILS 


only  on  the  under  side,  the  corresponding  dap  for  the  upper  post  being  cut  in 
the  end  plate,  which  is  not  shown;  in  Fig.  3  the  edge  of  the  dap  is  shown  both 
top  and  bottom,  and  in  Fig.  4  it  is  shown  on  both  upper  and  lower  sides  of  the 
plate. 

The  style  of  framing  shown  in  Fig.  i,  was  in  use  at  least  60  years  ago,  and  is 
about  the  only  style  of  framing  shaft  timbers  illustrated  in  old  works  on  mining, 
such,  for  instance,  as  Overman's  "  Metallurgy,"  published  in  1850.  There 
are  mines  where  this  peculiar  style  of  timbering  is  still  in  use,  but  it  has  nothing 
in  particular  to  recommend  it,  while  the  placing  of  the  end  plates,  unless  they 
are  provided  with  separate  hanging  bolts,  is  accomplished  with  difficulty,  which 


FIG.   I 


FIG.  3. 


FIG.  2.  FIG.  4. 

FIG.    40. — SHAFT   TIMBER   ENDS. 

is  not  the  case  with  any  of  the  other  methods  here  shown.  Fig.  2  represents 
the  end  of  a  wall  plate  halved  and  provided  with  a  dap  on  the  lower  side  to 
accommodate  the  post  of  the  set  below,  at  that  corner,  and  a  corresponding 
dap  must  be  cut  on  top  of  the  end  plate  that  will  rest  upon  it.  This  is  a  simple 
and  common  way  of  framing  timbers  for  vertical  shafts.  The  method  of 
framing  shown  in  Fig.  3  is  similar  to  that  in  Fig.  2,  the  only  difference  being 
in  the  bevel,  shown  at  B.  This  bevel  is  for  the  purpose  of  reducing  the  tendency 
of  the  timbers  to  split  under  heavy  side  pressure,  but  ordinarily,  where  the  side 
pressure  is  sufficiently  great  to  cause  timbers  to  split  when  framed  as  shown  in 
Fig.  2,  the  bevel  will  make  but  little  difference.  Neither  the  style  illustrated  in 
Fig.  2  nor  Fig.  3  is  well  adapted  to  shafts  which  depart  more  than  1 5°  from  the 
vertical. 

Timbers  for  inclined  shafts  are  now  framed  almost  universally  as  shown  in 
Fig.  4.  This  method  is  equally  adapted  to  either  inclined  or  vertical  shafts. 
It  will  be  noticed  that  the  so-called  dovetail  mortise  is  beveled  on  one  side  only, 
the  other  side  being  normal  (at  a  right  angle)  to  the  top  of  the  timber.  A 
modification  of  this  is  sometimes  seen  where  both  sides  are  cut  with  a  bevel. 
This  has  no  advantage  and  is  also  more  troublesome  to  cut.  All  the  marking 
in  the  laying  out  of  shaft  timbers  can  and  should  be  done  with  the  use  of 


SHAFT  WORK 


77 


a  templet.  This  should  be  made  of  a  good  sound  piece  of  wood,  for  the  back, 
to  which  should  be  secured  steel  plates  of  the  proper  size  and  shape  to  indicate 
the  various  cuts  to  be  made.  When  a  templet  is  used  there  are  fewer  mistakes 


Detail  of 
End  Plate 


r 

t 

=»        -1   "* 

i 

<  7—  -j—  > 

Detail  of 

r   T 

T 

Wall  Plate 

L       i 

i 

FIG.   41. — METHODS   OF  FRAMING   TIMBER. 


made  in  laying  out  the  work.  A  man  may  be  an  excellent  carpenter  and 
yet  know  nothing  whatever  of  laying  out  marks  for  framing  shaft  timbers. 
Then  too,  with  the  use  of  the  templet  all  the  timbers  are  framed  exactly  alike, 


78  HANDBOOK  OF  MINING  DETAILS 

all  cuts  corresponding  in  position  and  size,  which  is  sometimes  not  the  case 
when  the  work  is  laid  out  with  a  square,  unless  the  man  be  a  most  careful 
workman. 

Figure  41  shows  the  method  of  framing  shaft  sets  from  8-in.  timber  which 
is  probably  in  most  common  use.  It  combines  the  maximum  strength  with 
the  minimum  labor  of  framing.  Angles  other  than  right  angles  are  to  be 
avoided  as  far  as  possible.  They  are  hard  to  fit.  To  frame  this  joint,  fasten 
templet  to  side  A  of  wall  and  end  plates  and  frame  top  and  bottom  faces  of 
tongue  and  shoulder,  squaring  from  the  templet.  Also  frame  daps  for  posts 
at  center  of  wall  plates  and  mark  top  and  bottom  of  dap  for  the  divider.  The 
sides  may  be  framed  and  squared  from  these  faces  when  finished.  The  wedge- 
shaped  gain  on  divider  holds  the  divider  on  the  bottom  set  and  avoids  the 
deep  cut  in  the  wall  plate  necessary  for  a  tongue. 

The  false  set  which  protects  the  bottom  timbers  from  the  blasts  is  easier  to 
handle  if  made  of  half-round  logs  without  framing.  The  false  wall  plates  should 
completely  cover  the  shaft  wall  plates  and  be  attached  by  bolts  through  the  holes 
drilled  for  the  hangers.  The  false  end  plates  and  divider  need  only  reach 
from  one  false  wall  plate  to  the  other  and  holes  should  be  drilled  in  the  shaft-end 
plates  to  accommodate  bolts  in  the  same  manner  as  in  the  wall  plates. 




Extension  of  Wall  x 
Plate  used  in  Enlarged  x-»x 

Shaft. 


FIG.    42. — FRAMING   FOR   SHAFT   TIMBERS   TO  ALLOW   FOR  ADDITIONAL   COMPARTMENT. 

Method  of  Extending  Shaft  Timbers  (By  D.  A.  McMillen).— In  timber- 
ing shafts  it  is  often  necessary  to  devise  some  means  of  converting  an  end  plate 
into  a  divider  and  extending  the  wall  plate  so  as  to  add  another  compartment. 
In  the  ordinary  procedure,  when  adding  an  extra  shaft  compartment,  it  is 


SHAFT  WORK 


79 


often  cheapest  to  retimber  entirely  that  portion  of  the  shaft  which  is  to  be 
enlarged,  as  the  ordinary  wall  plate  serving  for  a  two-compartment  shaft  will 
not  do  for  one  of  three  compartments.  If  the  end  plate  of  the  two-compart- 
ment shaft  is  framed  in  the  beginning,  as  shown  in  Fig.  42  at  A  and  the  wall 
plate  on  the  side  to  be  extended  as  B,  it  is  comparatively  easy  to  add  an  extension 
C  to  the  wall  plate  and  to  fit  these  together,  making  the  timbers  B  and  C  act 
as  wall  plates,  and  A  as  a  divider  instead  of  an  end  plate.  The  scheme  thus 
simply  resolves  itself  into  a  matter  of  cutting  the  wall  plate  B-C  into  two  parts 
that  can  be  afterward  fitted  together.  A  block  to  conform  with  the  shape  of  D 
is  usually  fitted  into  the  open  space  that  is  left  before  the  timbers  of  the  extra 
compartment  are  added.  This  system  has  been  adopted  in  several  places  in 
the  Globe  district  and  has  proved  satisfactory. 

Shaft  Timbering  at  the  Keystone  Mine  (By  William  H.  Storms).— The 
Keystone  mine  at  Amador  City,  Calif.,  is  one  of  the  largest  mines  on  the 
famous  Mother  Lode.  It  has  been  extensively  developed  by  a  number  of 


JE^E 


^K^^Es^ 


FIG.    43. — METHOD    OF   TIMBERING   THE    KEYSTONE   SHAFT. 


incline  shafts  of  varying  depth,  the  deepest  being  the  Patton  shaft  near  the 
north  end  of  the  property,  which  was  started  by  W.  H.  Patton  over  40  years 
ago,  and  now  has  a  depth  of  1573  ft.  This  shaft,  beginning  in  the  slate  country 
rock,  at  a  depth  of  about  400  ft.,  is  approached  by  a  fissure  which  occurs  in  the 
hanging-wall  side  of  the  shaft  and  continues  in  or  near  it  to  about  the  8oo-ft. 
level.  The  ground  is  very  heavy,  and  has  for  years  been  a  source  of  annoyance 
and  expense  in  keeping  the  shaft  open.  Time  and  again  the  timbers  have 


8o 


HANDBOOK  OF  MINING  DETAILS 


been  reinforced  and  renewed  until,  in  some  of  the  worst  places  the  shaft  is 
supported  by  a  solid  crib  work  of  great  timbers.  One  effect  of  the  heavy  down- 
ward pressure  of  the  swelling  ground  on  the  hanging  wall  side  of  the  shaft  has 
been  to  force  the  caps  down  upon  the  ends  of  the  dividers,  causing  the  latter 
to  cut  deeply  into  the  caps,  thereby  weakening  the  timbers  and  reducing  the 
size  of  the  shaft,  hence  necessitating  frequent  repairs.  A  few  months  ago  a 
scheme  was  introduced  in  the  retimbering  of  the  Patton  shaft  which  has  been 
found  to  give  complete  satisfaction  and  which  is  evidently  going  to  result  in  the 


y2"Planks 

o  a^m"Boltsf  lifHoles                          12"X  12  "x  18  G"                 °  ° 

f 

]^tf* 

-1C" 

:  

10" 

,  3-10-- 

t-b' 

00 

v, 

_j      4>,n 

—  > 
i 

ir    Cage 

^f  5-betwee 

i  > 

i 

CM 

Ladder 

(M 

^     P 

S3 

T^^-i 

X 

Guides 

"o 

and  Pipes 

^ 

? 

0 

i 

4 

i 

T 

,4"x4" 

'£ 
Q 

v 

[o 

* 

Q  | 

V'x8" 

1 

^jsCounterw'tg 

\ 

^6ibt^>                                         12x12"                                           o  o 

II                                       Plan. 

91      1          ,2"x  2  'Strip,           r^-j 
-                             |             /.Spiked  on.            M                       1 

Ivwy 

v//, 

i!  !:                                      J                                                         i:  ;• 

'////, 

to 

1 

^lo- 

I 

Cedar  Post 
-"   10"Top          I" 

0) 

1 

1'4" 
Hanger  r; 
Bolts    ^ 

* 

| 

Q 

2"x  2"Strip 

A, 

'M 

i-        /                             V                                                   V                        i!     i! 

'////, 

MM 

1    6"C.I.*/^ 
LJ                                        L-JWashe/             L 
iSiHA  RlPvation.                              U     ^^ 

FIG.    44. — ROGERS    SHAFT   BELOW   CONCRETE    PORTION. 


saving  of  much  time  and  timber  in  repairing  this  shaft.  The  idea  is  illustrated 
in  Fig.  43.  It  is  simply  the  insertion  of  a  heavy  head  block  a  between  plate  b 
and  divider  d,  as  shown.  No  mortise  or  dap  is  cut  in  the  wall  plate,  and  the 
divider  is  sawed  off  square.  The  plate  timbers  are  18  in.  square,  the  dividers 
12 X  1 8  in.,  and  the  head  block  is  18  in.  wide,  24  in.  long  and  4  in.  thick.  It  is 
cut  as  shown,  and  is  slipped  in  between  the  wall  plate  and  the  top  of  the  divider 


SHAFT  WORK 


81 


and  held  in  place  by  driving  in  shingle  wedges.     The  pressure  soon  exerts 
itself,  however,  and  wedges  then  become  superfluous. 

Rogers  Shaft  at  Iron  River,  Michigan  (By  H.  L.  Botsford).— The 
accompanying  sketches,  Figs.  44  and  45,  illustrate  the  size  and  timbering  of  a 
new  shaft  which  the  Munro  Iron  Mining  Co.  is  sinking  at  a  property  near  Iron 
River,  Mich.  A  concrete  drop  shaft  has  been  sunk  through  the  overburden 
by  The  Foundation  Co.  of  New  York.  From  this  point  on,  the  sinking  will  be 
continued  by  the  mining  company  and  the  shaft  will  be  rectangular  in  section, 


Skip  Guide 


l"Bolta 


Bracket- 

K 

So; 

—  Bracket 

u 

Limit  of  Shaft  in  Ledge 

^ 

D 

I 

d 

Is 

"S3            8"x  16"x  H" 

6 

c. 

E 

P 

<     i| 

-?      ?3 

•f.s 

Plate  X 

^: 

£•£ 

2  8  'Ship  Channel.  \ 

/.—  J8S       J 

cc 

Detail  here. 
6'x  8"Guides                 \ 
zza                                     fa 

oc 

3 

^> 

m    ' 

fcr                      b 

8 

*.. 

«              5'2-                - 

S 

—  4  » 

^ 

1 

G.-L.-Bracket 

(Limit  of  Shaft  in  Ledge 

4-G-Lr-B  racket 

i 

"IS"  Ship  Chanr 
;        on  Edge. 

,el/       / 

: 

T  This  Distance 
f/       Varies. 

= 

~\  q*  :*<,';•?":  V?  •*<?•': 

^^<b*  *  %a-^^fri%*iV&iM(M!    *-.S-*S*g£ft^.*«» 

Note:-  Place  Channel  across  End  of  Skip 
Compartments  when  Guide  comes 
out  more  than  12  "from  Concrete. 


Compartments  when  Guide  comes  I>7vi>^»:**v?i!V^;^l 

out  more  than  12  "from  Concrete.  „   \'  'j    '  sj^-ig^!  [ 

When  less  than  12  "from  Concrete,  Coacrete.      i"Bolt/  Depth  of 

Suppoit  Guide  thus:  pjan   Timber  12 

Sets  spaced  8' Centers  Vertically. 
FIG.   45. — STEEL   WORK   IN   CONCRETE    PORTION   OF    ROGERS    SHAFT. 


11X16  ft.  6  in.,  inside  dimensions,  with  two  skip-compartments,  a  cage- way 
and  a  combined  pipe-  and  ladder-way.  One  end  of  the  latter  compartment  is 
arranged  to  accommodate  the  counter-weight  for  the  cage. 

Figure  44  shows  a  plan  and  side  elevation  of  the  shaft  as  it  will  be  con- 
structed below  the  concrete  portion.     The  skips,  which  will  be  operated  in 
balance,  are  of  liberal  width  to  facilitate  their  loading  through  the  chute  at  the 
6 


82  HANDBOOK  OF  MINING  DETAILS 

bottom  of  the  shaft.  In  the  past  it  has  been  found  that  where  the  skip  is 
narrow,  and  blocky  ore  is  hoisted,  considerable  trouble  is  experienced  by  the 
clogging  of  the  ore  in  the  loading  chute;  with  the  width  of  skip  as  designed,  it  is 
expected  that  this  difficulty  will  be  obviated.  The  cage  compartment  is  6X  n 
ft.  and  will  permit  the  operation  of  a  cage  large  enough  to  take  a  55-cu.  ft. 
saddle-back  tram  car,  this  being  the  size  of  the  underground  car  which  will  be 
used  in  the  mine.  The  size  of  the  cage  will  also  permit  the  hoisting  of  rock  on 
it,  if  this  is  found  to  be  necessary  during  the  ore-shipping  season.  Another 
advantage  of  the  large-sized  cage  is,  that  cars  may  be  loaded  with  mine  timbers 
at  the  timber  yard  on  surface,  trammed  to  the  shaft,  lowered  into  the  mine,  and 
taken  to  their  destination  underground  without  further  handling  of  the  timber. 
The  steelwork  which  will  support  the  guides  in  the  concreted  portion  of  the 
shaft,  and  the  bracket  for  attaching  the  steel  members  to  the  concrete  walls 
is  shown  in  Fig.  45.  These  sets  will  be  spaced  8  ft.  between  centers.  Bolts 
which  fasten  the  brackets  to  the  concrete  will  be  split  2  1/2  in.  on  the  bottom 
end  and  a  wedge  inserted  before  driving  them  in  the  holes  drilled  for  them  in  the 
concrete  wall ;  in  addition  they  will  be  leaded  in. 

While  the  initial  cost  of  such  shaft  construction  is  high,  the  advantages  are 
many.  Water  difficulties  are  overcome  to  a  large  extent  and  stability  and 
alignment  are  assured. 

Combination  Post  and  Set  Timbering  in  Shafts  (By  Claude  T.  Rice).— 
The  ground  in  the  inclined  shafts  that  follow  the  Calumet  &  Hecla  conglomerate 
is  so  heavy  that  a  crew  of  seven  men  is  kept  at  work  easing  the  timbers.  The 
manner  of  supporting  the  roof  when  it  becomes  bad  is  novel,  in  that  the  main 
part  of  the  top  weight  is  carried  on  posts  while  the  scalings  from  the  roof  are 
supported  by  lagging  carried  on  regular  shaft  sets.  When  the  shaft  is  first  sunk, 
only  the  posts,  or  the  "end  timbers,"  as  they  are  called  locally,  are  put  in,  and 
the  shaft  is  made  22X9  ft.,  but  after  a  time  the  weight  begins  to  come  on  the 
roof  and  the  shaft  pilla  s  begin  to  flake  away  under  the  pressure,  increasing  the 
width  to  about  25  ft.  by  the  time  that  the  shaft  sets  are  placed. 

The  posts  are  put  in  with  foot  and  head  blocks,  built  up  of  6-in.  pieces 
criss-crossed  to  make  a  head  block  1 8  to  24  in.  thick,  and  a  foot  block  about  12 
in.  thick.  Then  when  the  weight  comes  on  the  posts  the  crushing  of  these 
thick  head  blocks  gives  the  ground  a  chance  to  adjust  itself  to  the  new  conditions 
bafore  the  posts  are  injured.  The  posts  when  first  put  in  are  about  6  1/2  ft. 
long,  from  2  1/2  to  3  ft.  in  diameter.  Posts  of  Georgia  pine  last  about  two 
years  before  they  need  to  be  reheaded  and  will  stand  three  reheadings,  each  of 
which  lengthens  the  post's  life  two  years,  so  that  the  posts  have  a  life  of  seven 
or  eight  years  in  these  shafts.  Some  hemlock  posts  are  used,  which  last  about 
two  years  before  they  have  to  bs  replaced.  No  reheading  of  the  hemlock  posts  is 
possible,  as  they  rot  too  fast  for  it  to  pay.  A  few  hard-wood  posts  have  been 
tried,  but  lasted  scarcely  a  year,  rotting  into  a  mush-like  pulp,  in  an  amazing 
manner. 


SHAFT  WORK  83 

The  post  is  reheaded  as  soon  as  the  head  block  has  been  compressed  to  the 
limit  and  before  compression  of  the  post  itself  has  begun.  Owing  to  the  pieces 
in  the  head  block  being  laid  so  that  they  take  the  weight  across  their  fibers  instead 
of  along  them,  the  compression  is  confined  entirely  to  the  block  until  the  last, 
when  the  wood  fiber  has  become  so  compacted  that  it  is  as  firm  as  the  fiber  of 
the  posts.  This  reheading  consists  of  sawing  and  chiseling  out  a  cut  across 
the  top  of  the  post  so  as  to  allow  the  post  to  be  knocked  out.  About  6  in.  is 
lost  in  this  way  at  each  reheading.  Then  a  new  set  of  foot  and  head  blocks  is 
put  in,  and  the  post  is  good  for  another  two  years,  being  practically  as  strong 
as  when  first  put  in.  When  the  second  set  of  head  blocks  has  been  com- 
pressed to  the  limit,  the  post  is  again  reheaded,  but  before  the  post  has  had  to 
be  reheaded,  the  roof  will  have  begun  to  scale  off  partly  under  the  weight  and 
partly  because  of  swelling,  caused  by  oxidation  of  lime  minerals  in  the  hanging 
wall.  Lagging  has,  therefore,  to  be  put  in  over  the  skip  compartments,  and 
this  lagging  is  carried  on  regular  sets  such  as  are  commonly  used  in  inclined 
shafts.  Owing  to  the  swelling  of  the  foot  wall,  which  gives  especial  trouble 
through  raising  and  warping  the  tracks  so  that  the  skips  will  not  stay  on  them,  no 
sill  is  used  under  the  posts  of  the  shaft  set;  instead  foot  blocks  of  liberal  propor- 
tions are  used. 

The  lagging  rests  on  i4X  i4-in.  caps  of  pine.  In  a  shaft  having  two  hoisting 
compartments,  the  cap  is  in  two  pieces  that  butt  against  one  another  over  the 
manway,  which  is  placed  in  the  center,  as  shown  in  Fig.  46.  Above  the  cap 
proper  is  carried  a  false  cap  of  round  timber  whenever  there  is  sufficient  room. 
This  rests  on  blocks  placed  on.  the  cap  pieces  directly  over  the  posts.  Under 
the  cap  and  between  the  posts  and  the  cap  are  squeezing  pieces  of  6X  i4-in. 
timber,  about  24  in.  long,  with  their  ends  beveled  so  that  they  will  bend  and 
have  less  tendency  to  cut  into  the  caps.  The  squeezing  pieces  take  most  of  the 
crushing  in  these  sets,  as  by  them  the  pressure  is  distributed  over  a  larger  area 
on  the  cap  than  on  the  post.  In  other  words,  there  is  a  concentrated  pressure 
on  the  underside  of  the  squeezing  pieces,  and  a  distributed  pressure  on  the  top 
side.  Consequently,  the  post  cuts  up  into  the  underside  of  the  squeezing  piece, 
but  the  squeezing  piece  does  not  in  turn  cut  into  the  cap.  As  the  weight  comes 
end-on  on  the  fibers  of  the  post,  it  sustains  little  injury  when  it  cuts  into  the 
squeezing  piece. 

Studdles  are  put  in  to  brace  the  timbers,  always  at  the  bottom  and  generally 
also  at  the  top  of  the  posts.  In  order  to  provide  room  for  the  circulation  of 
air  between  the  stull,  or  end-timber  posts  and  the  square-timber  posts,  as  the 
shaft  sets  are  called,  a  3~in.  block  is  put  in  between.  This  prevents  decay 
starting  on  the  posts  where  the  two  would  otherwise  be  in  contact. 

In  easing  the  timbers,  the  men  work  on  top  of  the  lagging  that  is  carried  on 
the  square  timbers,  and  throw  the  rock  that  comes  from  the  easing  of  the  roof 
off  at  the  far  sides  of  the  shaft  so  it  can  be  scraped  down  to  the  level  and  loaded 
on  the  sides.  Some  of  it  cannot  be  prevented  from  falling  into  the  manway 


HANDBOOK  OF  MINING  DETAILS 


and  is  worked  down  to  the  level  that  way.  By  this  arrangement  the  timber- 
men  are  able  to  work  over  the  skipways  without  interfering  with  the  hoisting; 
indeed  it  is  to  accomplish  this  that  the  square  timbers  are  used. 


Longitudinal  Section  of 
Shaft  showing  Timbering. 


10-in.  Round  False  Cap 


Cross  Section 

FIG.   46. — POSTS  AND   SQUARE   TIMBERS   IN  AN  INCLINED   SHAFT. 

The  combination  of  posts  to  take  the  bulk  of  the  top  weight  with  sets  to 
carry  the  lagging  is  a  most  admirable  scheme  for  timbering  inclines  in  heavy 
ground,  for  it  throws  most  of  the  wear  and  tear  on  the  round  posts,  which  are 
the  cheapest  elements  in  the  combination  to  replace.  Moreover,  by  using  the 


SHAFT  WORK  85 

squeezing  pieces  the  caps  are  saved  from  injury  and  the  life  of  the  square- 
timber  sets  is  increased. 

The  manway  is  put  in  the  center  of  the  shaft,  so  that  the  men  who  replace 
the  rope  idlers  can  inspect  the  track  between  idlers  without  entering  the  skip 
compartments.  The  ladder  is  carried  on  pieces  of  timber  clamped  to  the  air 
main,  the  ladder  being  bolted  to  the  crosspieces  by  staples.  There  is  some 
objection  to  this  arrangement,  as  if  any  repairs  have  to  be  made  on  the  air- 
main,  the  ladder  has  to  be  removed.  Still  there  is  the  advantage  that  the 
ladder  is  kept  clear  of  the  ground,  so  that  rocks  cannot  accumulate  under  it 
which  is  one  of  the  things  that  has  to  be  guarded  against  in  an  inclined  shaft. 

Timbering  Swelling  Ground  (By  George  C.  McFarlane). — In  swelling 
ground  it  is  noticeable  that  the  swelling  is  always  at  right  angles  to  the  foliation, 
and  drifts  paralleling  the  stratification  may  require  double  setting,  while  the 
crosscuts  will  stand  without  timber.  I  have  also  noted  cases  where  drifts  in 
the  upper  workings  had  stood  for  years  without  retimbering,  while  below  the 
oxidized  zone  heavy  sets  were  crushed  and  broken  in  2  months.  As  a  rule  this 
swelling  ground  is  not  difficult  to  retimber.  Ground  that  is  heavy  because  the 
rock  is  loose  and  full  of  slips  often  comes  down  in  large  masses;  when  a  couple 


FIG.   47. — SHAFT   TIMBERING    IN   SWELLING    GROUND. 

of  sets  break,  the  fall  may  bring  down  adjacent  sets.  On  the  other  hand,  in  a 
drift  in  swelling  ground  the  timbers  may  be  crushing  and  binding  and  when  a 
broken  set  is  knocked  out,  only  three  or  four  wheelbarrow  loads  of  rock  will 
come  down. 

For  replacing  broken  shaft  sets  in  swelling  ground  I  devised  the  form  of 
timbering  shown  in  Fig.  47.  Two  sets  of  6X  lo-in.  timbers  with  a  6Xi2-in. 
filler  between  the  wall  plates  are  used.  One  side  of  the  6X  lo-in.  piece  and 
both  sides  of  the  filler  are  sawed  on  a  bevel  of  1/2  in.  as  shown.  In  sawing, 
the  bevel  cut  is  made  by  placing  a  bar  of  flat  iron  across  the  bunks  of  the  saw 


86  HANDBOOK  OF  MINING  DETAILS 

carriage  in  front  of  the  head  blocks  and  canting  the  stick  back  on  the  bar.  In 
placing  the  sets,  the  posts  must  be  put  in  tight,  using  two  or  more  jacks  to 
bring  the  plates  and  filler  to  a  solid  bearing  at  each  post.  In  sinking  a  new 
shaft  with  this  kind  of  timbering  the  set  would  be  gripped  together  by  hanger 
bolts  until  a  set  of  dead  logs  were  placed.  As  the  walls  of  the  shaft  swell, 
the  filler  is  of  course  forced  in  between  the  plates,  causing  the  posts  to  sink  into 
them. 

If  the  plates  and  filler  grip  tighter  on  one  side,  the  set  will  be  crowded 
toward  the  slack  side  as  it  takes  the  squeeze.  In  an  hour  or  so  between 
shifts  this  can  be  remedied  by  jacking  in  a  couple  of  extra  posts  on  the  slack 
side,  and  in  this  way  the  guides  can  be  kept  in  good  alinement.  This  form  of 
set  allows  the  walls  of  the  shaft  to  swell  4  in.  without  breaking  the  timbers. 
Should  the  swelling  force  the  filler  flush  with  the  plates,  pieces  of  lagging  can 
be  removed,  a  few  at  a  time,  the  wall  cut  back  a  few  inches  and  the  lagging 
reset  by  inserting  blocks  between  it  and  the  wall  plates.  The  posts  can  then 
be  removed  and  the  filler  jacked  out  with  a  couple  of  pipe  jacks,  the  posts 
reset  and  the  temporary  blocking  between  the  lagging  and  the  wall  plates 
removed.  One  set  of  posts  will  have  to  be  chopped  out  to  release  the  fillers 
of  the  first  set;  after  that,  many  of  the  posts  and  part  of  the  lagging  can  be 
recovered  in  shape  to  use  again. 

Placing  Shaft  Timber.— At  the  Iron  Blossom  mine,  in  the  Tintic  district, 
Utah,  shaft  sets  are  put  together  at  the  bottom  of  the  shaft  and  then  hoisted 
into  position.  When  a  set  of  timbers  is  to  be  put  in,  the  framed  pieces  are 
lowered  on  the  cage,  temporary  guides  being  used  so  as  to  allow  the  cage  to 
drop  below  the  point  to  which  shaft  timbering  has  advanced.  The  wall  plates 
are  laid  upon  a  5-ft.  board  placed  across  the  bottom  of  the  cage.  The  end 
plates  and  dividers  are  then  dropped  into  place  and  the  sets  drawn  tightly 
together.  Wooden  dowels  may  be  used  to  secure  the  framed  ends  to  the  wall 
and  the  end  plates.  When  the  set  is  put  together,  the  cage  is  hoisted  to  the 
proper  point  and  the  rigid  set  drawn  up  against  the  posts  by  hanging  irons  from 
the  next  set  above.  By  thus  making  up  the  shaft  set  before  it  is  put  into  position 
it  is  claimed  that  time  is  saved  and  more  rigid  sets  are  insured. 

Supporting  Guides  or  Runners  in  Shaft. — The  scheme  shown  in  Fig.  48 
for  the  support  of  shaft  guides  is  used  at  the  Tobin  and  Dunn  mines  at  Crystal 
Falls,  Mich.  The  guide  itself  is  5X8  in.,  and  is  fastened  to  the  shaft  timbers 
by  two  3/4-in.  lag  screws.  In  addition  to  this  a  3X3-in.  angle  iron  is  used 
every  10  or  15  ft.  in  the  shaft.  This  angle  iron  is  bolted  to  the  runner  with 
two  i/2X6-in.  bolts  and  fastened  to  the  shaft  timber  with  two  i/2-in.  lag 
screws.  The  original  method  was  to  use  only  one  lag  screw  in  the  center  of  a 
5X  6-in.  runner.  This  was  found  to  be  entirely  too  weak,  and  the  screws  almost 
invariably  broke  at  a  point  where  the  thread  begins.  With  the  present  arrange- 
ment the  runners  do  not  work  loose,  except  as  the  acid  waters  may  corrode  the 
bolts. 


SHAFT  WORK  87 

Holding  Shaft  Timbers  with  Wire  Cables.— The  Fremont  shaft,  at  the 
Fremont  Consolidated  mine;  near  Amador  City,  Calif.,  has  two  compartments 
and  dips  at  an  angle  of  52°.  It  is  650  ft.  deep  with  a  5o-ft.  sump,  and  is  true 
throughout  its  depth,  being  unquestionably  the  best  inclined  shaft  on  the 
Mother  Lode.  In  sinking  this  shaft,  some  heavy  ground  that  caved  badly  was 
encountered.  It  was  impossible  to  get  a  bearing  for  the  wall  plates  or  caps, 
and  the  more  the  ground  was  trimmed  away  to  secure  a  bearing  for  these  timbers, 


Side 


Back 


o     o 


FIG.    48. — METHOD    OF   SUPPORTING    SHAFT   GUIDES. 


the  worse  it  caved,  until  a  large  cavern  was  formed  above  the  shaft.  In  order 
to  timber  the  shaft  through  this  ground,  the  expedient  of  securing  the  timbers 
in  place  with  old  hoisting  cable  was  tried  and  proved  quite  successful.  The 
sets  in  the  caving  zone  were  tied  with  the  cable  to  those  above  which  had  firm 
bearings  in  the  wall  rock.  This  hanging  of  the  timbers  was  continued  until 
firm  ground  that  would  give  sufficient  bearing  for  the  timbers  was  again  encoun- 
tered. Stringers  were  then  placed  over  the  suspended  shaft  sets  and  upon  them 
a  cribbing  built  up  in  the  opening;  old  timbers  and  waste  were  stowed  in  it 


88 


HANDBOOK  OF  MINING  DETAILS 


until     it  was  entirely  and   tightly  filled.     No  trouble  has  since  been  experi- 
enced with  the  shaft  at  this  point. 

USES  OF  STEEL  AND  CONCRETE 

Steel  Shaft  Sets  on  the  Mesabi  Range  (By  F.  A.  Kennedy).— The  steel 
sets  used  by  the  Shenango  Furnace  Co.  in  its  Whiteside  mine  near  Buhl, 
Minn.,  are  illustrated  in  Fig.  49.  The  inside  measurements  are  6  ft.  X  18  ft., 
8  in.  The  wall  plates  and  end  pieces  are  5-in.  H's  weighing  18.7  Ib.  per 
foot,  with  lo-in.  I-beams  for  dividers.  The  sets  are  spaced  4  ft.  center  to 
center  and  held  together  with  eight  3  i/2-in.  angle  studdles.  All  angles  are 


3'x  3  x  %  x  20^ 
Connecting  Angla 

1 


3H-'  x  y/i  x  H  x  5 
Counseling  Angle 


FIG.    49. — STEEL   SHAFT   SETS   AT   WHITESIDE   MINE. 


shop  riveted  to  the  end  pieces  and  dividers  so  that  little  time  is  lost  in  putting 
a  set  in  place.  Machine  bolts  were  used  with  nut  locks  for  bolting  the  steel 
together.  The  shaft  was  wet  and  it  took  but  2  hours'  labor  at  the  most  to  put 
a  set  in  place.  Norway  planks  were  used  as  slats  and  are  held  in  place  by  means 
of  small  2Xi/2X2-in.  angles  shop  riveted  to  the  back  of  all  wall  plates  and 
end  pieces.  Later  on  it  is  proposed  to  replace  the  slats  by  concrete.  The 
sketch  shows  how  the  first  bearing  set  was  placed  under  the  second  set.  The 
rails  are  33  ft.  long,  resting  on  concrete  foundations  each  10  ft.  in  length. 
Another  bearing  set  of  i2-in.  X  i4-ft.  I-beams  was  put  in  when  the  rock  forma- 


SHAFT  WORK 


89 


tion  was  encountered.  Bearers  like  the  last  named  were  put  in  every  60  ft. 
down  the  shaft.  This  is  found  to  be  a  satisfactory  method  of  sinking. 

Arrangement  for  Guiding  a  Drop  Shaft. — The  sinking  of  the  W.  F.  2 
shaft  at  Obernkirchen,  South  Hanover,  Germany,  encountered  just  below  the 
surface  an  i8-m.  zone  of  watery  sand  and  clay,  necessitating  the  use  of  drop- 
shaft  methods.  The  manner  in  which  the  shaft  was  guided  in  the  true  vertical 
direction  is  of  interest,  and  is  illustrated  in  Fig.  50. 

The  inside  diameter  of  the  finished  shaft  was  required  to  be  4.5  m. ;  the  con- 
crete wall  of  the  drop  shaft  was  therefore  molded  to  an  inside  diameter  of 
5.5  m.,  with  walls  77  cm.  thick.  The  outside  of  the  wall  was  coated  with  cement 
plaster  and  then  smeared  thickly  with  brown  soap,  whereby  the  friction  of  the 
shaft  against  the  guides  was  greatly  reduced.  It  was  only  necessary  to  build 


Vertical  Section 


FIG.    50. ARRANGEMENT   OF   GUIDES    FOR   DROP-SHAFT   SINKING. 

the  walls  16  cm.  above  the  top  of  the  guides  to  maintain  the  weight  required 
to  give  a  steady  downward  motion.  The  sinking  went  on  without  incident  to  a 
depth  of  14.5  m.,  when  the  wall  refused  to  drop  further,  even  though  it  was 
heavily  weighted  and  the  top  built  up  to  a  height  of  3.16  m.  above  the  guides. 
It  was  ascertained  by  boring  that  a  further  depth  of  only  7  m.  was  necessary 
to  reach  solid  strata,  and  it  seemed  possible  to  gain  this  distance  by  forepoling. 
Before  this  plan  could  be  put  into  operation,  however,  an  inrush  of  material 
under  the  sinking  shoe  made  it  imperative  to  adopt  a  second,  interior  drop  shaft, 
made  of  sheet  iron.  The  bottom  of  the  concrete  shaft  was  firmly  puddled  with 
clay,  and  the  iron  drop  shaft,  of  4.95  m.  inside  diameter  and  15.8  m.  high, 
was  lowered  into  place. 

Sinking  by  this  means  went  on  rapidly  until  solid  strata  were  encountered 
at  a  depth  of  21.76  m.  The  shaft  was  continued  into  the  rock  to  a  further 
depth  of  6  m.,  leaving  3  m.  of  the  iron  wall  reaching  up  inside  the  concrete 
wall  of  the  outer  shaft.  The  space  between  these  two  walls  was  then  filled 


90  HANDBOOK  OF  MINING  DETAILS 

with  cement  grouting  (equal  parts  of  quick-setting  cement  and  sand)  by  boring 
holes  through  the  iron  plates  and  connecting  the  holes  with  pipes  reaching  to 
the  surface.  The  upper  20  cm.  of  the  space  was  filled  with  pitch-pine  wedging. 

The  first  5  m.  in  the  solid  rock  were  lined  with  cast-iron  tubbings  and  a 
masonry  bearing  ring,  behind  which  all  the  spaces  were  thoroughly  grouted. 
At  a  depth  of  32.6  m.  sinking  was  begun  in  the  ordinary  manner,  with  masonry 
lining. 

Concrete  in  Inclined  Shafts  (By  Sheldon  Smillie).— When  a  well  organized, 
well  advised  mining  company  commences  to  sink  a  shaft,  the  question  of 
durability  of  equipment  outweighs  that  of  first  cost,  and  for  this  reason 
concrete  has  in  some  places  gradually  superseded  timber  for  supporting  the 
walls  through  the  overburden.  Its  long  life  in  wet  shafts  and  its  freedom 
from  the  danger  of  fire  especially  commend  it.  For  use  in  vertical  shafts 
through  water-bearing  ground  it  has  been  employed  for  some  time,  but  only 
recently  has  it  been  applied  to  metal  mining  and  inclined  shafts. 

In  the  Lake  Superior  copper  region  all  new  shafts  are  equipped  with  concrete 
collars.  Concrete  runners  under  the  rails  have  not  yet  gained  the  popularity 
they  deserve,  but  are  coming  into  use  more  and  more.  The  collar  or  cribbing 
makes  an  absolutely  water-tight  joint  with  bedrock,  keeping  out  all  surface 
water,  is  free  from  rot  and  should  a  fire  occur  in  either  the  shaft  or  in  the  rock- 
house  above,  large  iron  doors  may  be  closed  to  make  an  effectual  barrier. 

Managers  have  installed  concrete  runners  experimentally  and  in  a  critical 
mood  have  found  absolutely  nothing  to  complain  of  except  that  a  fast-moving 
skip  makes  much  noise.  It  was  thought  that  with  rails  laid  rigidly  on  the  con- 
crete there  would  be  considerable  breakage  from  crystallization,  but  this  seems 
not  to  be  the  case.  In  my  opinion,  if  it  proved  a  source  of  trouble,  both  the 
breakage  and  the  noise  could  be  eliminated  by  inserting  a  strip  of  wood  between 
the  rail  and  the  concrete.  The  strip  could  be  replaced  without  much  trouble 
when  rotten,  and  would  furnish  little  combustible  material  in  event  of  fire. 
The  only  real  objection  ever  made  was  that  if  a  skip  went  off  the  track  it  would 
either  break  the  runners  or  would  become  so  tightly  wedged  that  the  runner 
would  have  to  be  broken  to  get  the  skip  out  and  valuable  time  would  be  lost 
making  forms  and  allowing  new  concrete  to  set.  This  might  happen  with 
small,  poorly  balanced  skips,  but  in  a  period  of  4  years  at  one  of  the  largest 
mines  of  the  district,  where  a  hoisting  speed  of  4000  ft.  per  minute  is  usual,  I 
do  not  recall  a  single  derailment. 

The  accompanying  sketches,  Figs.  51  and  52,  show  the  usual  designs  em- 
ployed. In  preparing  for  the  collars  the  shaft  is  carried  down  to  firm  bedrock, 
the  size  of  the  outside  dimensions  of  the  concrete,  the  temporary  lining  making 
the  outside  form  for  the  concrete.  When  sufficiently  firm  ground  is  reached, 
the  size  of  the  shaft  is  contracted  to  its  regular  dimensions,  forming  a  ledge 
upon  which  the  concrete  is  started.  The  inside  form  need  only  be  built  high 
enough  to  give  the  concrete  at  the  bottom  a  good  set  when  the  lower  frames  may 


SHAFT  WORK  91 

be  moved  above.     The  collar  can  be  built  to  any  height  required  by  dump 
facilities  and  tracks. 

The  walls  are  proportioned  according  to  the  depth  of  the  shaft,  the  concrete 
mixture  and  whether  or  not  reinforcing  is  to  be  used.  When  well  reinforced 
on  the  hanging  walls  with  old  rails,  rope  and  the  usual  collection  of  old  iron 
found  around  a  mine,  12  in.  is  probably  the  minimum  thickness.  To  make 
the  cribbing  water-tight,  care  must  be  taken  that  the  ledge  is  clean,  the  concrete 
well  tamped,  and  when  left  over  night  should  be  left  rough  and  well  wet  the 
following  morning.  For  this  purpose  a  fire  hose  attached  to  the  column-pipe 
will  be  found  convenient.  In  filling  in  the  concrete  a  chute  is  all  that  is  necessary 


Longitudinal  Section  of  Shaft. 


Ifl -  _  a 


Cross  Section  of  Shaft. 
FIG.    51. — SECTIONS    OF   INCLINED    SHAFT. 

for  shallow  work,  but  if  the  fall  is  too  great  the  sand  and  rock  tend  to  separate 
and  the  concrete  should  be  lowered  into  place.  When  first  finished  the  ground 
water  appears  to  seep  through  and  below  the  cribbing,  but  this  stops  in  time, 
due  probably  to  clogging  of  the  pores  of  the  cement. 

If  considerable  water  is  running  when  the  cribbing  is  installed  it  may  be 
necessary  to  drain  in  some  special  way  and  stop  the  holes  later  with  plugs.  In 
the  cribbing  the  dividers  and  runners  are  built  at  the  same  time  as  the  walls. 
The  dividers  between  the  compartments  are  concrete  posts  normal  to  the  dip 
about  1X2  ft.  in  section  and  spaced  at  6  ft.  centers. 

The  dimensions  of  the  runners  vary  with  the  type  of  skip  and  may  be  square 
or  battered;  12X12  in.  is  a  good  section.  One  mine  has  runners  14  in.  high 
with  a  i4-in.  face  and  16  in.  wide  at  the  base.  The  first  rails  are  anchored  by 
straps  to  the  runners  of  the  rockhouse  and  are  held  in  place  on  the  concrete  at 
intervals  of  3  ft.  by  a  pair  of  cast-steel  clips,  cast  to  fit  the  flange  of  the  rail. 


92 


HANDBOOK  OF  MINING  DETAILS 


Through  the  clips  3/4-in.  bolts,  heads  up,  pass  through  3/4-in.  galvanized 
pipes  set  in  the  concrete,  terminating  in  No.  20  galvanized-iron  boxes,  3X4X 
12  in.,  which  are  laid  transversely  in  the  runner.  The  box  permits  the  insertion 
of  a  washer-plate  and  nuts.  Some  companies  use  bolts  with  threads  at  both 
ends,  but  this  makes  tightening  difficult,  especially  if  one  nut  goes  on  hard  and 
the  other  easily,  and  the  threads  are  apt  to  wear  on  the  upper  end  with  any 
motion  of  the  rail.  Square  heads  and  nuts  are  preferable  as  offering  greatest 
purchase  for  a  wrench  and  least  wear.  For  tight  places  bolts  are  made  with 


Plan  of 
Shaft  Collar 

^ 
^ 

_Un.  Ledge  for 
Doors 

^     m 

% 

§ 

m 

Bevel  to  end         11 
•'of  ruuuers           x  — 

n        iM 

'Hy\                       f^tcx 

FIG.    52. — DETAILS    OF   CONNECTION    OF   CONCRETE    SHAFT   RUNNERS    WITH   WOODEN    RUNNERS 

OF   ROCK  HOUSE. 

hexagonal  heads  as  they  can  be  manipulated  more  readily.  Old  galvanized- 
iron  pipes  cut  to  proper  lengths  for  the  bolts  were  found  to  be  cheaper  than 
having  special  tubes  rolled  and  made  a  part  of  the  box.  A  piece  of  old  3-in. 
pipe  laid  outside  the  runner  permits  the  bell  rope  to  be  extended  into  the 
shaft  house,  and  a  piece  of  old  hoisting  rope  forms  a  good  core  for  supporting 
the  runners. 

In  finishing  the  top  of  the  collar,  provision  must  be  made  for  attaching 
the  runners  of  the  permanent  rock  house.  In  the  case  illustrated  in  Fig.  51,  the 
rock  house  was  to  have  a  channel  section  to  which  wooden  runners  would  be 
bolted.  Long  2-in.  bolts  were  to  be  placed  at  the  proper  distance  at  the  side  of 
each  runner;  these  would  lie  between  angles  riveted  back  to  back  on  the  back 
of  the  channel  and  the  bolts  would  tighten  down  on  a  washer-plate  at  the  upper 


SHAFT  WORK 


93 


end.  If  doors  are  to  be  hung  over  the  shaft  a  i-in.  length  should  be  made  all 
around  each  compartment  by  thinning  the  walls  by  that  amount,  and  the  neces- 
sary holes  for  bolts  and  lock  provided.  An  opening  is  left  at  the  side  of  the 
ladderway  to  admit  the  air  and  water  pipes  from  conduits  or  ditches. 

The  hanging  wall  of  these  mines  needs  little  or  no  support,  and  the  runners 
for  the  rails  are  built  directly  on  the  foot  wall  of  the  shaft,  saving  room  that  has 
hitherto  been  given  to  cross  ties.  They  are  similar  to  the  runners  in  the  collar, 
but  usually  a  little  higher  to  allow  for  the  irregular  foot  wall.  The  adhesion  to 
the  foot  wall  is  usually  neglected,  and  an  anchorage  made  of  drill  steels  set  at 
intervals  in  the  foot  wall  to  carry  the  entire  weight  of  the  runners. 

In  steeply  inclined  shafts  the  outer  ends  of  the  drill  steels  are  supported  by 
tie  bolts  from  ring  bolts  set  in  the  foot  wall  a  few  feet  above.  Tie  bolts  set  at 
intervals  in  the  concrete  outside  the  rails  support  the  rails  by  a  long  hanging 
bolt  bent  at  the  lower  end  and  passing  through  the  web.  The  guide  sheaves  for 
the  ropes  are  supported  on  structural- steel  cross  pieces  from  runner  to  runner 
laid  in  the  concrete.  Pulleys  for  the  bell  rope  are  screwed  into  wedge-shaped 
rocks  set  at  convenient  intervals  in  the  side  of  the  runner. 


FIG.    53. — SHAFT   TUBBING  ARRANGED    FOR   INJECTION    OF   GROUTING. 

Injection  of  Grouting  Behind  Shaft  Tubbing. — An  original  method  was 
employed  at  the  Hildesia  shaft  at  Diekholzen,  Germany,  for  insuring  a  perfectly 
water-tight  joint  between  the  upper  ring  of  a  set  of  tubbing  and  the  bearing  ring 
above  it.  As  the  tubbing  is  erected  from  below,  resting  on  a  similar  bearing 
ring  at  a  lower  point  in  the  shaft,  a  small  space,  of  variable  size,  always  remains 
around  the  top  of  the  uppermost  ring,  and  this  has  to  be  carefully  closed,  gen- 
erally with  pine  or  poplar  wedging. 

In  the  case  under  discussion,  illustrated  in  Fig.  53,  after  the  upper  ring  had 
been  put  in  position,  the  space  between  it  and  the  rock  wall  was  filled  with 


94  HANDBOOK  OF  MINING  DETAILS 

cement  grouting  to  the  level  d—df,  and  the  wooden  wedging  e  was  inserted  in 
the  usual  manner.  At  four  equidistant  points  around  the  shaft,  lo-mm.  holes 
/were  bored  through  the  wood.  At  four  other  equidistant  points,  45-mm.  holes 
g  were  bored  through  the  web  of  the  cast-iron  lining,  close  under  the  upper 
flange;  these  holes  were  fitted  with  pipes  and  couplings. 

By  means  of  hose,  one  of  the  latter  holes  was  connected  to  a  pipe  from  a 
high-pressure  pump,  and  cement  grouting  was  forced  into  the  space  i.  The 
three  other  holes  of  this  set  were  closed  as  soon  as  cement  began  to  come  through 
them,  with  the  escaping  air.  More  cement  was  injected,  until  it  began  to  escape 
through  the  holes  in  the  wedging,  and  these  were  then  tightly  closed.  Further 
additions  of  grouting,  under  a  pressure  of  80  to  90  atmospheres,  were  then 
applied,  for  the  purpose  of  forcing  the  cement  into  every  crevice  of  the  rock 
wall,  and  also  into  the  grain  of  the  wedging.  By  exercising  this  unusual 
precaution,  the  chance  of  leakage,  especially  during  the  winter  when  the  tubbing 
contracts,  was  entirely  overcome. 

Grouting  in  Quicksand. — A  new  method  of  grouting  in  quicksand  is 
given  in  Engineering  News.  A  pipe  large  enough  to  serve  as  a  cement-injection 
tube  is  fitted  at  its  lower  end  with  an  auger  point  and  a  helical-screw  blade;  just 
above  this  blade  several  holes  are  drilled  in  the  wall  of  the  pipe  and  fitted  for 
discharging  grout  outward  over  the  upper  surface  of  the  blade.  This  boring 
apparatus  is  twisted  down,  if  necessary  with  the  help  of  jetting,  by  water 
pumped  through  the  pipe.  When  it  reaches  the  desired  depth,  grout  is  pumped 
into  the  pipe,  and  at  the  same  time  the  drill  is  turned  backward  so  as  to  with- 
draw it.  The  grout  flows  out  along  the  face  of  the  blade,  and  becomes  mingled 
with  the  layer  of  sand  above  by  the  rotation;  the  resulting  mixture  is  passed  by 
the  turning  of  the  screw  blade  to  the  space  below,  where  it  builds  up  in  a 
cylindrical  body  corresponding  to  the  volume  swept  through  by  the  blade. 
When  the  drill  is  wholly  withdrawn,  it  may  be  sunk  again  alongside  the  first 
location,  and  thus  a  large  mass  of  contiguous,  coherent  cylinders  of  consolidated 
sand  can  be  formed.  The  process  is  patented  in  Germany. 

SHAFT  STATIONS  AND  SKIP  POCKETS 

Shaft  Station  in  Inclined  Foot  Wall  Shaft  (By  Claude  T.  Rice).— At 
the  mines  with  a  flat-dipping  vein,  in  the  Michigan  copper  district,  the  skips 
are  almost  universally  loaded  by  dumping  the  cars  directly  into  them.  Turn- 
tables are  used  for  switching  the  cars,  which  are  made  to  hold  approximately 
2  1/2  tons.  Generally  the  shafts  are  sunk  in  the  vein,  and  the  spur  tracks 
come  up  to  the  sides  of  the  shaft;  the  main  track  continues  through  to  the 
other  side  of  the  plat,  along  the  hanging  wall,  and  the  turntables  are  placed  in 
front  of  the  shaft  on  the  main  track  as  shown  in  the  small  drawing  in  Fig.  54. 
The  skips  generally  hold  7  tons,  so  that  it  takes  three  cars  to  make  a  load. 
Two  cars  stand  ready  to  be  dumped,  while  a  third  car  is  on  the  main  track. 


SHAFT  WORK 


95 


The  arrangement  of  the  station  at  the  3ist  level  of  Wolverine  No.  4  shaft 
which  is  sunk  in  the  foot  wall  about  25  ft.  from  the  vein  is  shown  in  Fig.  54. 
On  the  south  side  of  the  shaft  a  recess  is  cut  so  that  two  of  the  cars  can  be 
dumped  on  the  side,  the  third  car  being  dumped  from  behind;  on  the  north 
side  only  one  car  is  dumped  from  the  side  turntable  and  the  other  two  are 
dumped  from  behind,  the  empty  car  being  switched  over  to  the  side-dump 
track  to  get  it  out  of  the  way. 

On  the  south  side,  in  the  back  part  of  the  station,  it  will  be  noticed  that 
a  square  corner  is  cut.  This  was  for  the  small  hoist  used  in  sinking  the  shaft 


FIG.  2 
FIG.  54. SHAFT  STATIONS  IN  INCLINED  SHAFTS. 


deeper  from  that  level.  When  the  station  is  cut  in  this  way  a  brow  of  ground 
is  left  under  the  crosscut;  to  support  this  a  reinforced  concrete  pillar  is  put  in 
at  the  Mohawk  mine  before  the  brow  has  begun  to  give  any  trouble,  and  the 
floor  of  the  station  is  laid  with  reinforced  concrete,  6  in.  thick,  designed  to  stand 
a  load  of  400  Ib.  per  square  foot. 

Large  Underground  Station  in  a  Coeur  d'Alene  Mine.— One  of  the 
largest  and  most  complete  underground  timber,  boiler  and  hoist  stations  in 
the  United  States  is  newly  completed  at  the  Morning  mine  of  the  Federal 
Mining  &  Smelting  Co.,  Mullan,  Ida.  Its  construction  involved  several  inter- 
esting problems.  The  station  is  situated  at  a  point  nearly  2  miles  from 


96 


HANDBOOK  OF  MINING  DETAILS 


the  entry  of  the  No.  6  tunnel,  now  the  main  haulage  way  of  the  Morning  mine. 
In  this  tunnel  electric  haulage  is  used,  ore  being  handled  in  trips  of  fifteen 
5-ton  cars.  About  1000  tons  of  ore  are  produced  each  day,  and  practically 
the  entire  output  must  pass  through  this  station.  Ample  space  for  the  handling 
of  the  ore  and  timber  trains  was  therefore  a  prime  requisite  in  the  laying  out 
of  the  station. 

The  station  proper  is  100  ft.  long,  36  ft.  wide,  and  is  24  ft.  high  in  the  clear 
at  the  shaft,  dropping  to  a  height  of  n  ft.  at  a  point  200  ft.  distant.  There 
is  a  wide  double-track  approach.  A  boiler  room,  about  28 X  19  ft.  in  size, 
opens  off  from  the  farther  end  of  the  station.  Adjoining  the  boiler  room  is 
the  hoisting-engine  room,  30X47  ft.  in  size. 


.Hoisting 


FIG.    55. — GENERAL  PLAN  OF  TIMBER,   BOILER  AND  HOIST  STATIONS,   MORNING  MINE, 

MULLAN,    IDA. 

An  interesting  problem  arose  in  connection  with  the  placing  of  the  engine. 
A  shaft  with  compartments  4  ft.  8  in.  X  5  ft.  2  in.  in  the  clear  had  been 
decided  upon,  and  this  would  throw  the  sheave  wheels  5  ft.  6  in.  apart.  It 
was,  however,  deemed  wise  to  use  an  engine  similar  to  that  in  use  at  the  Mace 
mines  in  order  to  facilitate  repairs,  etc.  The  reels  on  this  engine  are  spaced 
4  ft.  8  in.  apart.  For  a  while  this  promised  to  make  trouble,  until  the  expedient 


SHAFT  WORK  97 

of  setting  the  engine  off  at  an  inclination  to  the  axis  of  the  shaft  was  hit  upon. 
The  crankshaft  of  the  engine  is  in  1/2  ft.  from  the  center  of  the  shaft  and 
inclined  from  its  long  axis  at  an  angle  of  31°  57'.  This  throws  the  sheaves 
at  the  proper  distance  apart. 

The  cableway  from  the  engine  to  the  sheaves  is  an  inclined  raise  through 
solid  rock  so  that  no  headframe  structure  is  required.  From  the  collar  of  the 
shaft  to  the  center  of  the  sheaves  is  100  ft.  An  old  hoist  set  in  line  with  the 
long  axis  of  the  shaft  will  handle  timber.  (The  sheave  for  this  is  only  45  ft. 
above  the  collar  of  the  shaft.)  The  general  layout  of  the  station  is  shown  in 

Fig-  55- 

Five  feet  from  the  wall  plate  of  the  shaft  is  an  ore  bin  26  ft.  long  (parallel 
to  the  long  axis  of  the  shaft);  it  is  25  ft.  wide  and  52  ft.  from  toe  to  top,  the 
bottom  having  a  45°  slope.  This  bin  was  excavated  out  of  solid  rock  and  is 
armored  on  the  front  inside  face  with  6o-lb.  rails.  Skips  automatically  dump 
ore  into  the  bins  from  which  it  is  drawn  directly  into  the  5-ton  cars  of  the 
electric  trains. 

In  cutting  out  the  station  some  interesting  rock  excavation  was  done.  The 
face  was  advanced  carrying  its  full  height  and  width.  To  do  this  four  lo-ft. 
bars  set  end  to  end  and  blocked  tight  with  3-in.  planking  were  used  across  the 
face.  The  line  of  bars  was  arched  slightly  toward  the  face,  from  which  it  was 
braced  with  the  wedge  timber.  This  formed  a  "compression"  truss  and 
although  many  miners  object  to  running  two  machines  on  a  bar,  on  the  score 
that  the  bar  will  not  hold  tight,  three  or  four  machines  were  continually  operated 
on  this  series  of  bars,  and  no  special  trouble  was  experienced  from  fitchered 
holes.  For  this  work  3  5/8-in.  piston  drills  were  used,  and  as  many  as  190 
eleven-foot  holes  put  into  a  round.  The  cuts  and  lifters  were  fired  first,  then 
the  other  holes.  Electric  battery  firers  were  used  in  all  cases.  One  round  of 
holes  usually  broke  enough  rock  to  fill  400  of  the  35-cu.  ft.  capacity  cars.  Only 
two  settings  of  the  bars  were  necessary  for  drilling  the  entire  face:  The  first 
was  on  the  muck  pile  and  the  second  lower  down  after  the  face  had  been 
mucked  clean. 

Concrete  Floors  for  Shaft  Stations. — At  the  Mohawk  and  Wolverine 
mines,  Michigan,  the  stations  at  the  inclined  shafts  have  reinforced-concrete 
floors  which  are  absolutely  fireproof  and  can  be  put  in  almost  as  cheaply  as 
timber  floors,  taking  into  consideration  the  sets  that  would  have  to  be  used  to 
carry  such  a  floor.  These  concrete  floors  are  made  6  in.  thick  and  are  designed 
to  carry  a  load  of  400  Ib.  per  square  foot.  The  reinforcement  used  by  W.  F. 
Hartman,  the  engineer  who  designed  the  floors,  consists  of  a  double  layer  of 
4-in.  triangular  mesh  reinforcement,  threaded  with  3/8-in.  strands  of  old 
hoisting  cable,  running  crossways  to  the  strands  of  the  triangular  mesh,  and  at 
6-in.  centers.  In  order  to  protect  the  reinforcement  from  fire  and  corrosion 
it  is  placed  about  i  in.  from  the  bottom  of  the  concrete. 

Skip  Pockets. — At  the  Bunker  Hill  mine,  near  Amador  City,  Calif.,  skip 
7 


98 


HANDBOOK  OF  MINING  DETAILS 


pockets  are  arranged  to  facilitate  the  handling  of  ore  and  waste.  The  usual 
custom  is  to  have  pockets  beside  each  other,  each  discharging  into  a  different 
shaft  compartment.  The  objection  to  this  is  that  it  permits  the  handling  of 
only  one  class  of  rock  in  each  compartment  from  any  level.  It  also  means  that 
trammers  must  switch  their  cars  to  the  proper  track  when  dumping  at  the  skip 
pockets.  The  shaft  at  the  Bunker  Hill  is  inclined,  having  two  hoisting  com- 
partments. To  overcome  the  objections  mentioned  above,  a  waste  and  an  ore 


FIG.    56. — ARRANGEMENT   OF   SKIP   POCKETS   AT   BUNKER  HILL   MINE. 

pocket  are  arranged,  one  over  the  other,  each  pocket  discharging  into  both  shaft 
compartments.  Below  levels  the  shaft  is  widened  out  to  three  times  its  regular 
height  and  is  carried  so  for  nine  sets.  The  compartment  above  the  shaft  is 
partitioned  off  as  a  waste  pocket  and  the  one  above  that  as  an  ore  pocket. 
The  timbers  between  compartments  are  heavily  lagged  and  lined  with  strips  of 
iron  off  the  guides  in  the  shaft.  By  this  arrangement  each  of  the  tracks  at  the 
station  serves  both  pockets  and  no  needless  switching  of  cars  is  necessary.  The 
accompanying  drawing,  Fig.  56,  illustrates  the  idea  of  the  skip  pockets.  Either 
ore  or  waste  may  be  drawn  at  any  level  whenever  desired.  With  such  an  arrange- 
ment only  a  single  track  is  required  at  stations. 

Skip  Pocket  and  Station  at  Leonard  Mine,  Butte. — In  Fig.  57  is  shown 
the  general  idea  of  the  arrangement  and  timbering  of  the  skip  pocket  and 
station,  on  the  i8oo-ft.  level,  in  the  No.  2  shaft  of  the  Leonard  mine  at  Butte, 
Mont.  The  .excavation  for  the  skip  pocket  is  started  at  a  point  five  timber 


SHAFT  WORK 


99 


sets  (25  ft.)  from  the  shaft.  It  is  carried  straight  down  for  two  sets  and  then 
benched  in  three  5-ft.  steps,  the  bottom  being  two  sets  wide.  From  the  bottom 
of  the  pocket  the  excavation  is  carried  down  the  width  of  the  shaft  for  three  sets. 
A  sheet-steel  gate  operated  by  a  compressed-air  cylinder  controls  the  dis- 
charge of  ore  from  the  pocket  into  an  apron,  also  of  sheet  steel.  The  lip  of  this 
apron,  when  lowered,  extends  over  the  edge  of  the  skip  so  that  the  ore  is  run 
directly  into  the  latter.  The  lip  of  the  apron  is  raised  and  lowered  by  com- 
pressed air.  To  operate  the  gate  and  apron,  a  man  stands  on  a  platform  on  the 
second  set  of  the  compartment  beside  the  shaft. 


V 

V 


/I 


Lagging  Packed  with  Waste 


Plat 


Open 


X,  -AirOpera'l 
jgj-Apron/ 

»rn/ 


'ted  Chute  Gate 


I/ 


/ 


FIG.    57. — SKIP   POCKET  AT    l8oO-FT.    LEVEL   OF    LEONARD    MINE,    BUTTE,    MONT. 

The  level  station  is  first  timbered  with  square  sets,  as  shown  by  the  dotted 
lines  in  the  sketch.  Two  8Xio-in.  stringers  are  then  run  out  under  the  top 
caps  for  three  sets,  one  end  of  each  stringer  being  blocked  up  from  the  shaft- 
wall  plate,  the  other  from  a  cap  of  the  third  set  from  the  shaft.  Support  is 
thus  given  to  the  roof  of  the  station,  while  the  first  two  sets  of  square-set  timber 
are  removed  and  replaced  by  the  permanent  station  sets.  Stringers  are  then 
blocked  up  in  a  similar  manner,  to  span  the  next  two  sets,  timbers  removed  and 
replaced,  etc. 

The  posts  of  the  station  sets  are  13  ft.  long,  made  of  i4Xi4-in.  timber,  12  X 
i4-in.  material  being  used  for  the  caps.  The  space,  usually  a  couple  of  feet 
high,  above  the  station  timbering,  is  filled  in  with  waste;  3-in.  lagging  is  used 
over  the  top  and  sides  of  the  station  sets. 


100  HANDBOOK  OF  MINING  DETAILS 

A  i-in.  space  is  left  between  pieces  of  lagging  to  allow  a  free  circulation 
of  air  and  thus  check  rotting  of  the  timbers.  A  station  may  be  carried  back  as 
far  as  is  necessary  to  provide  ample  room  for  handling  cars.  Beginning  with 
the  fourth  set  from  the  shaft,  the  bottom  of  the  station  should  be  raised  1/4 in. 
per  set  to  give  the  necessary  grade  to  the  approach.  The  station  at  the  Leonard 
mine  is  21  1/2  ft.  wide  and  provided  with  a  double-track  approach. 


DRIVING  ADITS  AND  DRIFTS 

Practical  Considerations  and  Methods — Timbering — Special 
Types  for  Heavy  Ground. 

PRACTICAL  CONSIDERATIONS  AND  METHODS 

Fast  Drifting. — Speeds  as  high  as  60  ft.  per  week  are  obtained  in  cross- 
cutting  the  slate  formation  in  the  Kennedy  mine  at  Jackson,  Calif.  Three 
shifts  are  worked  and  two  machines  run  on  one  bar.  As  soon  as  a  round  is 
fired,  the  bar  is  rigged  horizontally  across  the  face.  Then,  working  on  the 
muck,  the  two  drillers  put  in  the  back,  breast  and  cut  holes.  By  the  time 
these  are  in,  the  shovelers  have  cleaned  up  the  muck  pile  enough  to  allow  a 
lower  setting  of  the  bar  from  which  the  lifters  are  drilled.  In  this  manner  no 
time  is  lost  by  the  machine  men  in  waiting  for  the  muckers  to  clear  away  the 
rock  from  the  face,  and  each  man  can  put  in  his  full  shift  at  the  work  to  which 
he  is  assigned.  Such  small  refinements  of  methods  should  be  carefully  observed 
in  the  operation  of  a  large  mine  and  may  represent  the  difference  between  a 
profitable  or  losing  operation.' 

Maintaining  Grade  in  Driving. — In  driving  and  tunnel  work  the  miners 
unconsciously  tend  to  increase  the  grade  toward  the  face  at  a  steeper  angle 
than  is  desirable  for  drainage  or  for  favoring  the  tramming  of  loaded  cars. 
Too  much  grade  is  disadvantageous  because  the  grade  favoring  loads  is  so 
great  that  the  cars  tend  to  run  faster  than  considerations  of  safety  should 
permit;  greater  effort  is  required  to  move  empty  cars  up  the  grade;  natural 
ventilation  is  interfered  with,  the  results  being  especially  noticeable  at  the  face ; 
and,  in  some  cases,  the  unnecessary  loss  of  ore  in  the  backs  above  the  drift 
may  be  undesirable.  The  grade  of  drifts  in  some  of  the  older  mines  of  Corn- 
wall is  as  great  as  5%,  often  7%.  At  the  present  time  a  drift  is  rarely 
driven  at  a  greater  grade  than  i%,  which  is  twice  the  grade  recommended 
by  some  authorities.  To  avoid  driving  at  too  great  a  grade,  a  template  should 
be  provided  which  the  miners  can  use  as  often  as  they  desire  and  without 
losing  much  time.  Such  a  template  may  be  made  by  cutting  a  board  of  con- 
venient width  and  thickness  so  that  it  is  exactly  100  in.  long.  The  edges 
should  be  planed  true  and  parallel.  A  line  is  then  drawn  from  the  upper  corner 
of  one  end  to  a  point  i  in.  below  the  upper  corner  of  the  opposite  end  and  the 
board  sawed  along  this  line.  The  board  is  then  turned  over,  and  a  level- 
tube  let  into  the  edge,  which  is  so  adjusted  that  the  bubble  will  be  in  the  center 
of  the  tube  when  the  edge  of  the  board  is  in  a  horizontal  plane.  In  use,  the 

101 


102  HANDBOOK  OF  MINING  DETAILS 


is 'laid  <upbh  the  floor  of  the  drift  with  the  narrower  end  toward  the 
face.  Then  if  the  grade  of  the  floor  is  i%,  the  bubble  will  be  in  the  center 
of  the  tube. 

Alignment  in  Driving. — When  driving  on  a  vein  that  abruptly  passes 
from  a  relatively  uniform  rock  into  a  sheeted  zone  or  one  wherein  many  nearly 
vertical  fissure  planes  exist  in  close  proximity  miners  are  quite  liable  to  deflect 
the  direction  of  the  drift  to  one  side.  This  is  especially  true  when  the  vein 
crosses  or  enters  such  a  zone  at  an  obtuse  included  angle.  Due  to  the  way  in 
which  the  breaking  of  the  rock  is  influenced  by  the  fissures  or  joints  together 
with  the  tendency  to  advance  slightly  toward  the  direction  of  the  joints,  the 
drift  in  passing  through  such  a  zone  is  apt,  when  finished,  to  present  a  stepped 
in  or  jagged  appearance.  This  tendency  to  deflect  must  be  guarded  against. 

Placing  Holes  for  Blasting  (By  P.  B.  McDonald) .—The  subject  of 
placing  holes  for  blasting,  formerly  left  entirely  to  the  judgment  of  the  miner 
and  foreman,  has  lately  received  attention  from  engineers  and  superintendents. 
Wrong  judgment  in  placing  drill  holes  is  one  of  the  most  expensive  mistakes  in 
underground  work;  expensive  because  of  the  loss  of  explosives  and  time  in  the 
costly  operation  of  reblasting. 

The  following  is  an  incident  common  in  underground  practice:  A  miner 
drills  a  cut  of  say  12  holes  and  blasts  them.  If  the  ground  is  tough,  the  mis- 
placing of  one  hole  upon  the  breaking  of  which  the  effects  of  several  others 
depend,  may  spoil  the  blast  so  that  large  ridges  or  corners  are  left.  He  then 
cleans  or  blows  out  the  holes  which  failed  to  break  and  uses  from  10  to  40  sticks 
of  dynamite,  costing  10  cents  per  stick,  for  blasting  the  same  holes  a  second 
time,  In  almost  every  such  instance  one  or  two  extra  holes  or  a  closer  attention 
to  the  position  of  the  holes  drilled,  would  have  made  the  difference  necessary 
to  produce  a  successful  blast  in  the  first  trial.  The  time  spent  on  reblasting  is 
usually  more  than  would  have  been  required  for  the  added  care  in  placing  the 
holes,  and  the  greater  powder  cost  and  the  time  consumed  waiting  for  the 
smoke  to  clear,  are  distinct  losses.  The  nature  of  rock  excavation  is  such  that 
a  5%  closer  attention  to  details  may  mean  a  25  %  gain  in  results. 

The  simplest  form  of  blasting  is  slicing  or  breaking  to  an  open  face.  In 
open-cut  excavation,  holes  are  drilled  at  a  distance  back  from  the  face  a  little 
less  than  the  depth  of  the  hole,  although  this  distance  is  shortened  in  tough 
igneous  rock  and  where  the  blasted  portion  is  held  at  the  ends  as  in  drawing 
back  a  narrow  stope.  A  favorite  arrangement  of  holes  for  use  on  bench  work 
in  open-cuts  is  shown  in  Fig.  i.  (References  are  to  the  illustration  numbered 
Fig.  58.)  The  horizontal  holes  are  fired  at  the  same  time  as  the  vertical  holes, 
in  this  manner  deepening  the  cut  broken. 

In  drifting  in  soft  rock,  such  as  friable  schist  or  crumbly  slate,  most  of  the 
standard  arrangements  of  holes  give  good  results  and  the  misplacing  of  one  or 
two  does  not  usually  matter.  The  arrangement  shown  in  Fig.  2  is,  of  course, 
applicable  only  to  soft  rock  where  the  blasting  shatters  the  rock  so  thoroughly 


DRIVING  ADITS  AND  DRIFTS 


103 


Section 


O 


Plan 

FIG.    I. 


FIG.    2. 


FIG.    3. 


FIG.    4. 


FIG.    5.  FIG.    6. 

FIG.    58. — ARRANGEMENT   OF   DRILL  HOLES   IN   OPENCUT  AND   TUNNEL   WORK. 


104  HANDBOOK  OF  MINING  DETAILS 

that  it  can  be  picked  out.  Fig.  3  shows  a  lo-hole  cut  with  one  back  hole, 
frequently  used  in  driving  small  drifts  where  it  is  desired  to  keep  the  back  well 
arched.  The  arrangement  shown  in  Fig.  4  is  suited  to  larger  square  drifts. 
These  holes  would  not  break  much  hard  rock  because  of  the  distance  between 
the  bottoms  of  the  cutting-in  and  squaring-up  holes. 

It  will  be  noted  that  Figs.  3  and  4,  depicting  standard  cuts  in  soft  rock, 
show  two  classes  of  holes,  the  cutting-in  holes,  and  the  squaring-up  holes  which 
determine  the  shape  of  the  drift.  In  hard  rock  there  are,  in  addition,  what  are 
conveniently  called  relief  holes,  because,  situated  and  fired  intermediately 
between  the  cutting-in  and  the  squaring-up  holes,  they  relieve  the  ground  to  be 
broken  by  the  latter  set.  It  is  in  the  drilling  of  such  a  cut  that  the  best  judg- 
ment is  required,  for  relief  holes  are  a  changeable  feature  and  slight  variations 
in  the  toughness  of  the  ground  and  the  size  of  the  workings  necessitate  differently 
placed  relief  holes  for  successive  cuts. 

The  most  important  rule  to  be  observed  in  placing  holes  is  that  the  deter- 
mining factor  is  not  the  distance  apart  of  the  starting  points  of  the  holes  but  the 
distance  between  their  bottoms.  The  upper  few  feet  break  out  into  the  drifts 
comparatively  easily,  but  the  inner  portion  breaks  with  more  difficulty.  For 
instance,  in  Fig.  4  the  tops  of  the  holes  are  2  1/2  ft.  apart,  while  between  the 
bottom  of  the  cutting-in  and  the  bottom  of  the  squaring-up  holes  is  4  ft.  of  rock, 
so  that  in  hard  ground  the  cut  would  not  break.  Experience  in  any  variety  of 
rock  will  show  what  unit  may  be  figured  upon  for  the  dividing  distance  of  the 
bottom  of  the  hole,  usually  2  or  2  i  /  2  ft.  The  distance  from  the  cutting-in  to 
the  relief  holes  is  made  less  than  from  the  relief  to  the  squaring-up  holes  (figur- 
ing between  bottoms  in  each  case) ;  possibly  the  former  is  2  ft.  and  the  latter 
21/2,  because  ostensibly  the  squaring-up  holes  have  a  better  chance  to  break 
out  in  the  space  enlarged  by  the  relief  holes  than  the  relief  holes  have  in  the 
confined  space  made  by  the  cutting-in  holes. 

In  planning  the  arrangement  of  holes  the  first  consideration  is  to  get  a 
cutting-in  hole  that  will  break  well.  The  smaller  number  of  holes  used  for 
this  the  better,  because  it  is  essential  that  cutting-in  holes  be  fired  simultane- 
ously, and  owing  to  irregularities  in  the  rate  of  burning  of  fuse,  this  is  difficult 
to  accomplish  when  a  large  number  of  holes  are  to  be  fired;  also,  starting  a 
cutting-in  hole  is  often  difficult  because  of  the  angle  at  which  the  drill  point  has 
to  meet  the  face.  The  excavation  made  by  three  holes  meeting  at  a  point  is 
almost  as  large  as  by  five  or  six,  so  that  it  is  usually  better  to  use  only  three  or 
four  holes  for  cutting-in;  and,  if  the  ground  requires  them,  to  put  the  extra 
holes  in  as  relief  holes  where  they  will  break  more  ground. 

After  deciding  upon  the  cutting-in,  the  squaring-up  holes  are  placed  along 
the  sides,  bottom  and  top,  with  the  ground  equally  divided  between  their  bot- 
toms. Perhaps  two  relief  holes,  one  on  each  side  of  the  cutting-in  holes  will 
suffice ;  Fig.  5  shows  two  on  either  side  and  one  above,  helping  the  middle  back 
hole,  which  is  important  because  upon  its  breaking  depends  the  successful 


DRIVING  ADITS  AND  DRIFTS 


105 


blasting  of  the  other  two  back  holes.  In  the  sketch  the  cutting-in  holes  are 
placed  low;  they  might  have  been  shifted  higher  and  the  upper  relief  holes 
placed  underneath.  Quite  a  common  alternative  is  to  shift  the  cutting-in 
holes  to  right  or  left,  so  that  relief  holes  are  required  on  but  one  side;  thus  in 
Fig.  6  it  is  seen  that  the  cutting-in  holes  are  to  the  right  and  high. 

To  sit  in  the  office  and  figure  the  arrangement  of  holes  for  a  cut  is  not  satis- 
factory, unless  the  sketch  is  drawn  to  scale,  because  it  is  easy  to  draw  the  holes 
out  of  proportion  without  regard  for  practical  considerations.  The  holes 
cannot  be  pointed  at  such  an  angle  as  is  sometimes  desirable  because  the  crank 
end  of  the  machine  will  strike  the  sides  or  back  of  the  drift.  It  is  generally 
good  practice  to  drill  as  few  dry  holes  as  possible,  and  this  throws  out  many  of 
the  cuts  drawn  by  men  who  never  helped  drill  a  sticky  back-hole;  also  it  should 
be  aimed  to  economize  on  movements  of  the  arm  and  bar. 

An  inexperienced  man  examining  the  holes  for  a  cut  is  apt  to  think  that  the 
deviation  of  the  holes  is  at  too  small  an  angle,  and  that  the  holes  are  too  straight. 
It  is  not  an  easy  matter  to  tell  definitely  where  the  bottom  of  the  holes  will 
come,  but  by  inserting  long  drills  or  tamping  rods  into  the  holes  and  noting  the 
deflection  or  convergence  of  the  protruding  ends  the  relative  location  of  their 
bottoms  can  be  gaged. 

Drifting  with  Stope  Drills  (By  Horace  Lunt). — In  the  Cripple  Creek 
district  the  small  hammer-type  air  drills  have  almost  entirely  replaced  the 


FIG.    59. — FOOT   FRAME   FOR   STOPING   DRILL. 

piston  drills  in  stoping.  Much  of  the  work  is  done  by  leasers,  who  are  not, 
as  a  rule,  able  to  maintain  a  large  equipment  of  tools,  and  they  have  found  that 
where  the  ground  is  not  too  hard  they  can  successfully  use  stope  drills  for 
drifting.  Sometimes  the  drill  is  supported  by  a  sprag  across  the  drift,  but  a 
befter  scheme  is  the  simple  A-frame  illustrated  in  Fig.  59.  This  is  constructed 
of  2 -in.  plank  and  is  held  in  position  by  a  sprag  across  the  drift  as  shown.  The 
sprag  has  to  be  moved  once  or  twice  during  a  round,  but  this  does  not  take 
much  longer  than  changing  the  height  of  the  arm  on  the  column  of  a  piston 


106  HANDBOOK  OF  MINING  DETAILS 

machine.  All  thp  holes  except  the  lifters  are  given  an  upward  slope;  they 
are  put  in  nearly  horizontal  and  cleaned  with  a  blowpipe  connected  to  the  air 
supply. 

Driving  Inclined  Raises  with  Stoping  Drills  (By  Arthur  O.  Chris- 
tensen) . — The  usual  practice  is  to  drive  raises  to  connect  levels  for  ventilation, 
or  to  prospect  veins  or  the  country  above  tunnels,  as  small  as  is  possible  to 
work  in,  to  drive  them  perpendicular,  and  to  timber  with  pairs  of  stulls  3  1/2  or 
4  ft.  apart.  In  the  case  of  such  work  I  have  found  two  styles  of  raise  easier, 
cheaper  and  safer  to  drive  than  the  type  mentioned.  The  first  is  a  type  of  in- 
clined raise  which  is  described  below.  The  second  is  a  type  of  vertical  raise 
described  in  the  following  article. 

The  inclined  raise  may  be  run  at  any  desired  angle  in  the  vein,  or  may  cut 
through  the  country  rock.  The  advantages  of  it  are  that  it  requires  no  timber ; 
it  advances  horizontally  as  well  as  perpendicularly;  for  short  distances  it  pros- 
pects ground  more  cheaply,  and  is  more  rapidly  driven  than  a  drift  or  vertical 
raise.  No  mucking  is  required  and  a  "buzzer"  (hammer  stoping  drill)  can 
be  used.  By  making  the  raise  incline  about  40°  the  muck  runs  down  into  the 
chute  at  the  bottom  of  itself.  Only  occasionally  it  is  necessary  to  scrape  down 
some  of  the  dirt  which  packs  on  the  bottom. 

For  raises  steeper  than  40°  it  is  well  to  put  a  light  stull  or  piece  of  lagging 
across  the  bottom  of  the  raise  every  4  or  5  ft.,  and  not  over  a  foot  above  the 
bottom.  Dirt  fills  in  behind  these  and  they  form  steps  making  it  easier  to 
climb  up,  and  aiding  in  rigging  up  a  brace  for  the  machine  at  the  breast.  These 
steps  also  serve  to  catch  steel  tools  which  are  accidentally  dropped  by  the  miner. 

The  materials  required  to  make  a  set-up  are  a  few  pieces  of  plank  of  varying 
lengths,  wedges  and  spikes.  With  these  it  is  always  possible  to  brace  the 
machine  for  any  hole,  although  frequently  moiling  has  to  be  done  to  get  a  suitable 
hitch  for  the  plank  on  the  roof.  From  Fig.  60  an  idea  may  be  gained  of  how 
to  rig  a  plank  against  which  to  brace  the  machine  and  of  a  satisfactory  round 
of  holes. 

By  frequent  use  of  the  scraper,  or  by  using  hollow  steel,  flat  or  even  down 
holes  can  be  drilled,  although  such  holes  are  seldom  needed  in  driving  a  raise. 

To  clean  the  face,  set  up  at  the  breast  and  be  ready  to  drill,  need  not  take 
over  an  hour,  and  if  the  tools  do  not  have  to  be  carried  far  it  is  often  possible  to 
get  started  in  half  that  time.  To  put  in  the  round  of  about  eight  holes,  averaging 
3  ft.  deep,  takes  about  i  1/2  or  2  hours.  In  good  ground  with  no  mishaps 
3-ft.  holes  with  a  small  sized  Waugh  require,  on  the  average,  only  10  minutes 
each.  The  largest  size  drills,  using  larger  steel,  drive  4-ft  holes  in  the  same 
time.  If  a  nipper  brings  the  powder  to  the  miner  it  is  possible  for  him  to 
shoot  twice,  thus  making  4  ft.  a  shift.  Otherwise  2  1/2  ft.  is  as  much  as  can  be 
expected  for  a  daily  average. 

After  advancing  30  or  40  ft.  it  is  well  to  cut  a  station  or  pocket  in  the  side 
of  the  raise  in  which  to  keep  the  machine  tools,  etc.  To  cut  this  pocket  usually 


DRIVING  ADITS  AND  DRIFTS  107 

requires  two  rounds.  Sometimes  pockets  are  run  10  or  20  ft.  in  the  form  of  in- 
clined drifts  from  the  raise  with  the  purpose  of  prospecting  the  walls.  Such 
drifts  serve  as  very  convenient  stations  in  which  to  store  planks,  etc.  It  is 
often  well  to  timber  the  pocket  to  protect  the  tools  kept  in  it,  and  to  keep  them 
from  rolling  out  or  getting  buried.  Where  it  is  not  attempted  to  shoot  twice 
a  shift  all  this  is  easily  done  after  the  regular  round  is  drilled.  During  two 
consecutive  days  rounds  are  shot  out  of  the  side,  and  on  the  third  day  the 
pocket  thus  formed  is  timbered.  The  timbering  required  is  simple,  and  takes 
a  man  only  a  couple  of  hours  to  place. 

By  putting  in  a  pocket  every  30  or  40  ft.  an  inclined  raise  of  this  character 
can  be  carried  up  as  far  as  200  ft.,  although  to  climb  up  such  a  distance  becomes 
difficult,  and  it  requires  time  to  keep  the  dirt  from  piling  up  on  the  bottom 
and  filling  the  raise.  The  vertical  distance  made  by  such  a  raise  is  only  60 
to  70%  of  the  total  distance  covered,  yet,  by  being  able  to  shoot  two  rounds 


FIG.    60. — MACHINE   SET   UP   IN   INCLINED    RAISE. 

in  the  breast  each  shift,  except  on  those  days  when  cutting  or  timbering  a 
pocket,  it  is  possible  to  advance  vertically  faster  than  with  a  vertical  raise. 
Then,  too,  ground  is  being  prospected  horizontally  to  the  extent  of  70  or  80%. 
of  the  length  of  the  raise.  For  these  reasons,  for  prospecting  a  vein  short 
distances  above  a  tunnel  this  form  of  raise  seems  cheapest  and  most  speedy. 

Driving  Vertical  Raises  with  Stoping  Drills  (By  Arthur  O.  Christensen) . 
—In  driving  a  vertical  raise,  especially  on  a  narrow  vein,  I  find  that  greater 
speed  can  be  made  in  the  long  run,  greater  safety  maintained,  more  vein  mate- 
rial broken  in  proportion  to  waste,  and  the  raise  can  be  run  up  indefinitely 
with  but  little  increased  labor  as  the  raise  progresses  if  the  system  described 
herein  is  used.  Such  a  raise  is  made  narrow,  i.e.,  3  or  not  over  4  ft.  wide,  but 


io8 


HANDBOOK  OF  MINING  DETAILS 


6  or  8  ft.  long.     This  shape  allows  of  easily  putting  in  a  round  with  the  "  buzzer  " 
machine.     The  smallest-sized  machine  should  be  used. 

Stulls  are  placed  in  pairs  4  or  5  ft.  apart,  one  being  put  across  the  middle, 
and  the  other  across  the  end  of  the  raise.  The  stulls  placed  in  the  middle  must 
be  directly  over  one  another,  or  at  least  in  line,  for  they  are  to  form  the  partition 
between  the  manway  and  chute.  It  is  well  to  let  the  raise  incline  slightly 
toward  the  chute  side  so  that  the  broken  rock  in  falling  will  wear  against  the 
rock  at  the  chute  end  of  the  raise  rather  than  against  the  lagging  between  the 
compartments.  Except  for  the  last  two  pairs  of  stulls  the  middle  ones  are 


FIG.    6l. — STATION  AND    TIMBERING    IN   VERTICAL   RAISE. 

lagged  up  as  the  raise  progresses  and  ladder  and  pipe  line  are  carried  along,  as 
shown  in  Fig.  61.  The  condition  of  the  raise  after  the  round  has  been  put  in 
and  the  holes  are  ready  to  be  loaded  is  here  shown. 

At  the  beginning  of  the  shift  it  is  first  necessary  to  clean  the  muck  from  the 
platform  at  the  top,  and  to  pick  down.  This  done,  a  few  planks  are  placed 
across  the  chute  from  the  middle  stull  of  the  next  to  the  top  set.  This  keeps 
any  tools  or  steel  from  falling  into  the  chute.  I  find  it  well  to  spread  a  piece  of 
canvas  over  these  planks  to  make  them  tight.  Two  long  planks  are  then  laid 
across  the  top  platform,  extending  to  the  chute  end  of  the  raise.  These  are 
securely  spiked  down  at  the  manway  end.  To  prevent  accident  from  the  nails 


DRIVING  ADITS  AND  DRIFTS  109 

pulling  out  it  is  well  to  bind  the  ends  of  the  planks  down  to  the  stull  with  baling 
wire.  An  opening  is  left  between  these  planks  on  the  chute  end  through  which 
the  miner  can  climb. 

The  machine,  steel  and  tools  are  next  brought  to  the  top  from  where  they 
are  kept  in  a  pocket  or  station  cut  in  the  side  of  the  manway  below.  Short 
planks,  blocks  and  such,  necessary  for  rigging  the  machine,  are  kept  on  the  top 
platform.  They  serve  to  prevent  it  from  being  broken  by  the  rock  shot  down 
onto  it. 

This  whole  operation  takes  about  11/2  hours.  A  round  of  about  10  holes 
takes  2  or  2  1/2  hours,  so  that  by  dinner  time  the  round  is  in  and  the  tools  and 
machine  again  put  away.  After  dinner  hitches  must  be  cut  or  stulls  put  in. 
It  is  well  to  cut  the  hitches  one  day  and  the  next  day  put  in  the  stulls  and  move 
up  the  platform  and  ladder  if  needed.  Every  30  or  40  ft.  it  is  necessary  to  cut  a 
pocket  in  which  to  keep  the  machine,  tools,  etc.  To  cut  this  pocket  usually 
requires  two  rounds,  which  are  shot  at  the  same  time  as  the  regular  round. 
An  hour  or  an  hour  and  a  half  is  required  to  timber  this.  The  pipe  line  must 
also  be  run  up  from  the  former  pocket.  To  timber  the  raise,  make  these  pockets 
and  put  in  the  pipe  line  and  ladderway  keeps  one  man  pretty  busy.  Yet  it 
makes  a  desirable  job  for  a  good  miner  and  does  not  require  him  to  unduly 
strain  himself. 

The  scheme  of  placing  the  round  of  holes  depends  on  the  ground,  the  shape 
of  the  breast  and  the  sort  of  vein  being  followed.  In  general  it  is  well  to  put  in 
two  rows  of  holes,  one  on  each  side  of  the  vein.  These  holes  should  be  staggered 
rather  than  in  pairs.  Sometimes  it  is  best  to  put  from  five  to  eight  holes  on 
one  side  of  the  vein,  and  then  to  bring  down  the  vein  with  three  or  four  holes 
placed  back  of  it.  In  each  case  the  round  must  be  suited  to  the  shape  of  the 
breast  and  character  of  the  rock.  By  having  the  raise  with  its  long  axis  with 
the  vein  a  deep  round  can  be  drilled.  If  it  were  possible  to  keep  up  with  the 
timbering  a  4-ft.  round  could  be  drilled  at  each  shift.  When  one  man  is  doing 
it  all,  however,  he  must  limit  the  depth  of  his  round  to  the  amount  of  timber- 
ing, etc.,  which  must  be  done  the  next  shift. 

Not  including  cost  of  timber,  tramming  of  dirt,  sharpening  steel  and  com- 
pressing air,  the  cost  of  driving  a  raise  of  this  character,  when  run  by  a  good 
hustling  miner,  should  not  be  over  $3  per  foot,  and  under.favorable  conditions, 
considerably  less.  Doing  every  bit  of  work  in  connection  with  driving  such  a 
raise  by  myself  I  have  driven  67  ft.  a  month,  shooting  each  shift.  During  that 
time  there  was  only  one  missed  hole  and  no  case  of  holes  going  out  of  turn.  I 
attribute  this  success  to  the  care  taken  in  loading  the  holes  and  in  spitting  the 
fuses. 

Staple  for  Temporary  Staging  (By  B.  M.  Concklin).— In  Fig.  62  is  shown 
a  staple  for  supporting  temporary  staging,  that  is  used  in  the  mines  of  the  Oliver 
Iron  Mining  Co.  on  the  Mesabi  Range.  One  of  these  hooks  is  driven  into  each 
of  the  posts  of  two  adjacent  sets  and  on  both  sides  of  the  drift.  A  pole  is  then 


no 


HANDBOOK  OF  MINING  DETAILS 


laid  in  the  two  staples  on  each  side  of  the  drift  and  across  these  a  platform  of 
lagging  is  laid  as  shown  in  the  illustration.  The  staples  can  be  readily 
removed  with  a  bar  after  the  staging  has  served  its  purpose  and  has  been  taken 
away. 


FIG.    62. — STAGING    STAPLE  AND    MANNER   OF   USING    IT. 


TIMBERING 

Special  Types  for  Heavy  Ground 

Framing  for  Tunnel  Sets.  —  One  of  the  most  satisfactory  styles  of  framing 
tunnel-set  timbers  is  shown  in  Fig.  63.  This  style  is  used  in  the  Bunker  Hill 
mine  near  Amador  City,  Calif.,  and  also  on  the  Comstock.  This  style  of 
timbering  is  equally  well  adapted  for  round  or  squared  timbers.  The  wide 
notches  give  a  large  bearing  surface  to  take  up  side  or  vertical  pressure,  and 
make  this  method  of  timbering  admirable  for  drifts  in  heavy  and  swelling 
ground. 


l/2  Dap  for  Sprag 


FIG.    63. — DRIFT   SET   FOR  HEAVY   GROUND. 

Comparative  Strength  of  Several  Styles  of  Framed  Timber  Sets  (By 
K.  C.  Parrish). — I  would  have  some  scruples  about  adopting  the  style  of  drift 
sets  described  in  the  preceding  article  because  of  the  experience  I  had  several 
years  ago  in  holding  heavy  ground.  Conditions  in  one  place  were  such  that  the 
sets  would  be  down  in  6  weeks  if  not  relieved;  both  caps  and  posts  would  be 
half  moons.  Sawed  icX  10-  or  i2Xi2-in.  caps  and  posts  had  to  be  relieved 


DRIVING  ADITS  AND  DRIFTS  in 

every  morning  in  certain  sections  of  the  oreshoot.  This  meant  that  every  stick 
was  overloaded,  hence  the  exceptional  opportunity  for  trying  out  different 
styles  of  framing. 

The  desideratum  is  that  a  stick  should  be  so  framed  that  it  will  not  be  weak- 
ened by  splitting,  but  will  break  first.  Several  methods  of  notched  framing 
similar  to  that  shown  in  Fig.  63  were  tried,  but  it  was  found  that  any  cuts  in 
the  post  or  cap  weakened  the  timber,  especially  the  post,  which  split  most  easily 
when  cut  with  two  notches.  The  simplest,  cheapest  and  strongest  method 
found  was  that  shown  in  Fig.  64.  For  this  practically  no  framing  is  required. 
Caps,  posts  and  sills  are  sawed  the  proper  length  and  shape  and  a  3-in.  plank 


FIG.    64. — FRAMING   FOR  TUNNEL   SET. 

A  is  spiked  to  the  lower  side  of  the  cap  with  six  3o-dwt.  spikes,  thus  obviating 
the  necessity  of  cutting  into  any  of  the  sticks.  It  was  found  that  a  8-in.  square 
timber  framed  in  this  fashion  would  apparently  stand  as  much,  if  not  more, 
than  loX  lo-in.  material  framed  with  notched  caps  and  posts.  A  i  i/2-in. 
plank  was  used  with  8X8-in.  timber,  a  2-in.  for  loX  lo-in  timber,  and  a 
2  i /2-in.  one  for  i2Xi2-in.  timber.  These  planks  held  the  posts  so  that 
they  would  break  at  almost  any  point  before  they  would  split.  The  planks 
never  buckled  or  slipped.  This  method  was  found  to  save  much  time  in  both 
framing  and  placing  the  sets  and,  above  all,  it  gave  much  better  service. 

There  are  several  possible  reasons  for  the  failure  of  the  notched  timber 
sets;  one  is  the  impracticability  of  getting  a  perfect  fit,  hence  producing  unequal 
strains,  and  causing  excessive  pressure  at  certain  points,  and  thus  a  tendency 
to  split.  The  post  generally  tends  to  split  at  the  second  cut  and  near  the 
middle  of  the  stick.  This  is  probably  due  to  the  fact  that  the  outer  portion 
of  the  post  is  softer  than  the  central  portion  and  so,  upon  the  compression  of 
the  post  against  the  cap,  the  load  is  thrown  on  the  inner  cut,  causing  splitting 
there  before  the  outer  edge  is  sufficiently  compressed  to  take  its  share  of  the 
load.  In  other  words,  it  seems  that  even  if  a  timber  framed  as  in  Fig.  63  is 
fitted  perfectly,  the  difference  in  the  texture  of  the  wood  in  various  parts  of  the 
same  stick  is  such  that  the  timber  will  be  apt  to  split  before  breaking.  To 


112  HANDBOOK  OF  MINING  DETAILS 

get  the  maximum  efficiency  of  a  stick,  it  should  be  under  uniform  compression, 
whether  on  the  end  or  on  the  side,  and  separate  fibers  of  the  same  stick  should 
not  be  subjected  to  varying  strains.  Of  course  the  strengths  of  separate  fibers 
cannot  be  judged  nor  the  compression  regulated,  hence  the  obvious  advantage 
of  distributing  the  load  uniformly. 

Reinforced  Concrete  in  a  Tunnel. — The  Snake  Creek  drainage  and 
working  tunnel  at  Park  City  will  be  driven  between  14,000  and  15,000  ft. 
from  Snake  Creek  to  secure  deeper  drainage  for  the  mines  of  the  district  than 
is  at  present  available,  and  to  open  the  Bonanza  Flat  section  in  the  southern 
part  of  the  camp.  About  2000  ft.  from  the  portal  some  extremely  bad  ground 
was  encountered,  which  could  not  be  held  with  ordinary  timbering.  A  system 
of  reinforced  concrete  has  been  evolved  which  will  be  used  for  about  300  ft. 

The  section  is  egg  shape  with  the  small  end  down.  The  reinforcement  con- 
sists of  5o-lb.  rails  bent  hot,  in  two  pieces,  these  being  set  at  4-ft.  intervals. 
At  the  top  of  the  tunnel  arch  and  above  the  rails  is  another  rail,  the  whole 
being  covered  with  triangular  mesh  screen  weighing  109  Ib.  per  100  sq.  ft. 
A  shell  of  from  12  to  15  in.  of  concrete  is  put  on  the  outside  of  the  screen,  and 
the  space  between  the  concrete  and  the  roof  filled  with  green  quaking  asp,  to 
take  up  the  first  shock  of  settling  ground.  The  tunnel  has  room  for  two  tracks. 
It  is  7  ft.  high  from  the  tracks  to  the  center  of  the  arch,  and  9  ft.  across,  with 
a  4  i/2X9-ft.  waterway  under  the  track;  8X8  ties  are  placed  at  4-ft.  intervals. 
About  100  ft.  of  reinforced  concrete  has  been  completed,  and  this  method  of 
holding  the  ground  promises  to  be  successful.  Where  ordinary  timber  was 
used  in  certain  places  in  the  tunnel  it  was  squeezed  up  to  a  4-ft.  opening,  so 
that  special  measures  were  necessary.  The  part  completed  is  holding  well. 

A  Method  of  Mining  in  Heavy  Ground  (By.  W.  L.  Fleming). — The 
method  here  described  is  used  extensively  in  the  soft  slates  and  serpentines  of 
California.  It  is  also  useful  in  running  through  caved  stopes  and  slide  rock 
on  mountain  sides.  Timbers  are  framed  in  the  usual  manner,  but  instead  of 
being  kept  at  a  distance  from  the  working  face,  each  set  is  put  in  place  as  soon 
as  room  has  been  made  for  it.  If  blasting  is  necessary  at  all,  the  holes  are 
drilled  by  hand  and  the  light  charge  of  powder  required  does  little  or  no  injury 
to  the  timber.  Split  lagging  is  mostly  used  though  sawed  plank  is  better  if 
obtainable  at  a  reasonable  price.  An  assortment  of  widths  from  3  in.  to  8  in. 
is  necessary.  It  is  rare  that  face  boards  are  needed  to  prevent  running  of  the 
ground,  but  when  occasion  to  use  them  arises,  they  are  held  in  place  by  sprags 
from  any  available  support,  usually  the  nearest  set.  The  ground  will  usually 
sustain  itself  until  the  drive  is  several  feet  under  roof.  Then  the  first  two  sets 
are  placed  and  lagged  as  closely  as  is  necessary,  the  lagging  resting  directly 
upon  the  collar  set  and  upon  a  bridge  on  the  breast  set.  Sets  are  placed  4  ft. 
center  to  center,  and  lagging  4  ft.  6  in.  to  5  ft.  in  length  is  used.  Sills  are  not 
used  as  frequently  as  they  should  be  and  the  result  is  seen  in  the  uneven  appear- 
ance of  many  tunnels  and  the  frequent  repairs  necessary. 


DRIVING  ADITS  AND  DRIFTS 


In  Fig.  65  is  shown  a  set  at  a  breast  with  the  lagging  L,  resting  on  the  bridge 
B,  which  is  a  piece  of  lagging  or  plank  held  from  the  timbers  by  the  wedges  W. 
In  the  spaces,  a  a,  the  lagging  for  the  next  set  is  inserted  and  driven  forward 
as  the  breast  is  advanced.  Referring  to  Fig.  66,  which  is  a  vertical  section 


FIG.      65. — DRIFT     TIMBERING      IN      RUNNING      GROUND. 

lengthways  through  the  center  of  the  tunnel,  the  operation  is  as  follows.  Sup- 
pose set  A  s  in  place  with  the  breast  at  M  N.  Lagging  L  L,  is  pushed  under 
the  bridges  on  posts  and  cap  of  set  A  and  driven  up  to  breast  M  N.  The 
breast  is  worked  forward  by  pick  or  drill  and  each  piece  of  lagging  is  driven 


Bridge 


FIG.     66. — SECTION  ALONG   DRIFT   SHOWING   METHOD    OF    PLACING    SETS. 

forward  as  the  ground  in  front  of  it  is  taken  out.  When  the  breast  has  reached 
X  Y,  a  false  set  C,  of  light,  roughly  framed  timber,  is  set  in  place  to  guide  and 
support  the  lagging  as  it  is  driven  forward.  When  the  breast  reaches  O  P,  the 
set  B  is  placed  and  the  bridges  put  on.  Then  C  is  removed,  allowing  the  driven 
8 


114  HANDBOOK  OF  MINING  DETAILS 

lagging  to  rest  on  the  bridges  of  B.  The  wedges  sustaining  the  bridges  on  A 
are  next  withdrawn,  allowing  the  lagging  of  the  previous  set  to  press  the  bridge 
evenly  against  the  forward  lagging  which  rests  directly  on  A.  New  lagging  is 
now  driven  under,  bridges  on  B  to  the  breast  O  P,  and  the  operation  repeated. 

Driving  in  Loose  Ground  (By  George  J.  Young). — In  driving  a  drift 
through  loose  or  running  ground  fore-poling  is  commonly  resorted  to.  A 
modification  of  the  method,  in  use  on  the  Comstock  Lode,  is  worthy  of  mention. 
This  method  is  of  particular  utility  where  the  drift  must  be  supported  by  face 
boards.  Ordinarily  two  settings  of  the  face  boards  are  required  for  each  ad- 
vance of  one  set  of  timbers,  the  first  setting  just  beyond  the  position  to  be  occu- 
pied by  the  false  set,  the  second  just  beyond  the  regular  set. 

In  the  Comstock  modification  the  top  laths  are  driven  one-half  their  length, 
the  upper  face  boards  being  removed  and  the  loose  ground  carried  at  such  an 
angle  as  to  prevent  it  from  running  into  the  drift.  The  laths  are  then  supported 


&i^vS2#$$?%S$%^ 

FIG.    67. — BOOM   METHOD    OF   TIMBERING    IN   DRIFTING   THROUGH  HEAVY   GROUND. 

by  a  "boom,"  which  is  a  wooden  lever,  an  8X8-in.  timber,  9  to  10  ft.  long. 
The  boom  rests  upon  the  post  which  acts  as  a  fulcrum  and  one  end  carries 
sufficient  blocking  to  catch  up  the  top  laths,  the  other  end  being  held  down  by 
blocking  and  wedges  between  the  end  and  a  neighboring  cap.  The  boom 
is  rigged  along  the  center  of  the  drift.  The  top  and  upper  side  laths  are  then 
driven  forward  to  their  full  length  and  the  upper  face  board  placed  in  position. 
The  remaining  side  laths  are  then  driven  successively  and  the  face  boards 
placed  in  position.  On  the  completion  of  the  advance  the  next  regular  set  is 
placed.  A  single  setting  of  the  face  boards  thus  secures  an  advance  of  one 
regular  set.  In  square-setting  old  fillings  the  boom  is  also  used  and  obviates 


DRIVING  ADITS  AND  DRIFTS  115 

the  necessity  of  putting  up  temporary  props  in  the  working  space.  The  method 
of  rigging  the  boom  is  shown  in  Fig.  67. 

False  Set  for  Spiling  Ground  (By  James  Humes). — The  tunnel  being 
driven  by  the  Austin-Manhattan  Consolidated  Mining  Co.,  at  Austin,  Nev., 
is  7  ft.  wide  at  the  bottom,  6  ft.  at  the  top  and  8  ft.  in  height.  The  timber  used 
is  mostly  ioXio-in.  Oregon  pine.  The  posts  are  cut  8  ft.  long  and  placed 
in  hitches.  The  caps  are  4  i  /  2  ft.  in  the  clear. 

When  I  assumed  charge  of  the  underground  operations  of  this  company 
the  old  style  of  false  setting  for  spiling  ground,  which  was  sure  though  slow, 
was  in  use.  The  cost  was  high  on  account  of  the  large  amount  of  timber 
consumed  (which  costs  here  $40  per  thousand) ,  for  the  same  braces  that  would 
answer  for  one  set  of  breast  boarding  would  not  do  for  the  next  and  the  tunnel 
was  always  littered  with  discarded  breast-board  braces.  It  was  only  rarely 
that  we  could  get  in  one  set  of  timbers  in  24  hours,  and  as  all  costs  were  charged 
up  against  this  work  of  retimbering  they  amounted  to  more  than  $40  per  ft. 
for  the  spiling  ground. 

This  excessive  cost  set  us  thinking,  and  the  result  was  the  production  of  a 
false  set  that  increased  the  footage  driven  in  the  worst  ground  about  10  ft 


FIG.  68. — A  FALSE  SET  FOR  DRIVING  THROUGH  LOOSE  AND  HEAVY  GROUND. 

per  week  over  our  previous  work.  When  we  are  sure  we  have  reached 
ground  that  is  to  be  spiled  we  stand  the  last  set  loosely,  holding  the  posts  in 
an  upright  position  by  spiking  a  2  X  6-in.  plank  from  the  last  set  of  timbers  in 
place  to  each  of  the  posts  of  the  set  about  to  be  erected  (M  in  Fig.  68) .  These 
pieces,  and  a  temporary  block  placed  on  the  center  of  the  cap  and  against  the 
ground,  hold  the  timbers  in  position  until  the  side  bridging  F  is  put  in  place 
and  blocked. 

We  are  now  ready  to  place  the  top  bridging  A ,  which  consists  of  a  3  X  6-in. 
piece  supported   on*4X4X6-in.  blocks  C,  one  on  each  end  and  one  in  the 


Ii6  HANDBOOK  OF  MINING  DETAILS 

center  of  the  cap.  These  blocks  are  generally  removed  as  the  spiling  is  placed 
in  position.  After  the  spiling  is  driven  home  the  space  between  the  bridging 
and  the  spiling  is  filled  with  wedges  which  are  taken  out  when  the  further  end 
of  the  spiling  is  let  down  on  the  bridging  of  the  next  set. 

While  driving  the  spiling  ahead,  a  6  X  6-in.  tailing  block  L  is  used.  This 
tailing  block  should  be  sufficiently  long  to  engage  at  least  half  of  the  spiling; 
oftener  it  should  be  long  enough  to  reach  across  all  of  them  and  should  be 
moved  up  as  the  spiling  is  advanced.  When  driving  the  back  spiling  there 
should  also  be  at  least  two  side  spilings  advancing  on  each  side;  these  should 
be  kept  as  far  up  as  the  back  spiling.  While  driving  the  back  and  side  spiling, 
one  man  uses  a  light,  sharp-pointed  bar  with  which  he  removes  the  rock  from 
before  the  spiling  while  his  partner  is  forcing  them  up  with  a  i2-lb.  hammer. 

When  the  spiling  is  advanced  3  or  3  1/2  ft.  ahead  of  the  last  main  set,  the 
loose  rock  is  pulled  down  to  make  room  for  the  swing  posts  K,  but  none  of  it 
is  shoveled  out  of  the  way  into  the  cars  until  the  swing  set  is  pulled  up  tight 
against  the  spiling.  Leaving  this  loose  rock  as  shown  in  the  drawing  helps 
to  sustain  the  mass  hanging  overhead.  When  the  false  cap  is  placed  on  the 
swing  posts,  the  posts  and  cap  are  drawn  up  tight  against  the  spiling  by  screwing 
up  on  bolt  Q,  the  foot  of  the  posts  in  the  meantime  being  held  in  position  by  the 
bolt  T  and  also  supported  by  the  block  O.  The  fact  that  this  set  can  be  pulled 
up  tight  in  this  way  is  one  of  its  advantages,  for  it  obviates  the  necessity  of  driv- 
ing wedges  over  the  cap  and  against  the  spiling,  the  jarring  of  which  sometimes 
results  disastrously. 

Everything  is  now  ready  to  force  the  spiling  in  to  its  full  length,  and  when 
this  is  done  we  are  ready  to  go  on  with  the  breast  boarding.  The  boards  are 
held  in  place  by  the  iron  braces  TV  which  have  right  and  left  screws  or  threads. 
The  center  pieces  or  nuts  are  made  of  2-in.  pipes  plugged  at  the  ends  and  tapped 
for  the  extension  pieces,  and  have  holes  drilled  in  them  to  admit  a  small  bar. 

The  end  or  foot  piece  of  the  brace  next  to  the  breast  board  is  a  part  of 
the  rod  bent  at  the  angle  shown.  Each  end  of  this  foot  piece  is  turned  over 
into  a  slight  point  so  that  when  it  is  backed  up  tight  it  presses  into  the  plank  and 
prevents  slipping.  The  other  end  of  the  brace  is  rounded  and  fits  into  a  hole 
about  an  inch  deep  bored  in  the  swing  posts. 

These  braces  have  not  failed  in  a  single  instance,  neither  has  any  part  of 
the  swing  set.  It  has  often  happened,  in  the  old  method  of  timbering,  that 
downward  pressure  on  the  breast  boards  would  push  the  braces  below  a  hori- 
zontal position,  and  then,  of  course,  they  would  fall  out  and  leave  the  breast 
boards  unsupported;  but  these  iron  braces  can  be  placed  at  such  an  angle 
above  the  horizontal  that  the  downward  pressure  on  the  breast  boards  cannot 
drive  them  out  of  place. 

The  leaning  post  H  shown  in  the  center  of  the  tunnel  is  used  for  bracing 
the  center  of  the  breast  boards  when  the  extension  braces  are  taken  out  to 
admit  of  the  main  posts  being  placed  in  position.  It  is  also  customary  to  place 


DRIVING  ADITS  AND  DRIFTS  117 

a  plank  upright  against  the  breast  boards  and  overlapping  all  of  them,  and  it 
is  against  this  plank  that  the  braces  are  placed.  The  hole  in  the  swing  posts 
for  the  eyebolt  T  is  made  large  enough  to  admit  of  the  above  adjustment. 
When  everything  is  in  proper  position  and  the  chains  are  pulled  up  tight,  this 
eyebolt  is  also  tightened. 

The  miners  like  this  method,  for  when  they  reach  a  point  where  there  is  a 
cave  of  considerable  height,  they  can  put  this  swing  set  in  position  under  the 
protection  of  the  last  main  set.  They  can  then  place  plank  or  heavier  material 
from  the  last  set  over  the  false  set  and  thus  protect  their  heads  until  they  have 
the  next  main  set  in  position. 

The  side  spiling  is  worked  forward  as  fast  as  the  breast  boards  are  put  in 
place  and  overlapping  them;  this  and  the  support  the  side  spiling  receives 
from  the  swing  posts  is  sufficient  to  keep  them  in  place  until  the  main  set  is 
put  up.  There  are  only  two  side  spilings  shown  in  place  in  the  drawing, 
but  it  is  frequently  necessary  to  spile  the  sides  to  the  bottom  of  the  tunnel. 

Drift  Timbering  for  Heavy  Ground. — On  the  Mother  Lode  of  California 
especially  where  mining  is  conducted  in  the  black  Mariposa  slates,  great 
difficulty  is  experienced  in  keeping  the  drifts  open.  It  is  not  uncommon  to  see 
huge  drift  timbers  crushed  and  splintered  within  two  weeks'  time.  Occasion- 
ally drift  sets  require  retimbering  so  often  that  by  the  time  a  stope  is  worked  out 
the  drift  below,  originally  8  ft.  high  in  the  clear,  will  be  barely  high  enough  to 
allow  the  passage  of  an  ore  car.  It  is  usually  considered  economical  to  run  the 
drifts  in  the  orebody.  Above  the  drifts  in  the  Kennedy  mine  at  Jackson,  a 
system  of  carriers  on  stringers  is  used  to  support  the  stope  filling  above.  The 
usual  method  of  timbering  drifts  in  such  heavy  ground  is  illustrated  in  Fig.  69. 
The  cap  of  the  tunnel  set  is  blocked  against  the  walls  and  blocks  set  above  the 
posts  carry  the  stringers,  locally  termed  sills.  These  in  turn  support  the  carrier 
timbers  which  extend  across  the  drift  and  are  also  blocked  against  the  walls 
by  head  boards.  The  flooring  of  the  stope  is  laid  on  these  carriers.  In  most 
cases  the  horizontal  swell  or  pressure  of  the  walls  is  sufficient  to  hold  the 
carriers  so  firmly  that  they  will  support  the  stope  filling  during  any  necessary 
replacement  of  drift  sets.  In  this  manner  the  drifts  are  kept  open  for  their  full 
height  and  plenty  of  head  room  is  assured  in  the  main  passageways  of  the 
mine. 

Finger-pin  Timbering  in  Swelling  Ground. — The  finger-pin  method  of 
protecting  drift  sets  in  swelling  ground  was  devised  on  the  Comstock  Lode, 
and  has  been  in  use  there  several  years.  In  it,  as  can  be  seen  in  Fig.  70,  the 
lagging  is  held  back  against  the  swelling  ground  by  means  of  finger  pins,  as 
they  are  called,  pieces  of  fir  2  X  2  in.  in  section,  about  6  in.  long  and  sharpened  at 
their  small  end  to  a  diameter  of  about  an  inch.  Two  of  these  pins  are  put  in 
at  each  end  of  a  plank,  with  the  larger  end  against  the  post  as  the  pressure  on 
that  end  is  less  per  square  inch  than  that  on  the  small  end  of  the  pin.  The 
pin  therefore  is  forced  through  the  lagging  as  the  ground  swells,  and  the  lagging 


n8 


HANDBOOK  OF  MINING  DETAILS 


is  impaled  upon  the  pins.  In  this  way  the  posts  are  protected.  As  soon  as  the 
ground  has  swelled  so  that  the  lagging  is  almost  forced  against  the  posts,  the 
ground  is  eased  off,  pieces  of  2-in.  plank  are  put  in  to  cover  the  holes,  and  again 
the  planks  are  impaled  on  the  pins. 

The  drawback  to  the  simple  sprag-pin  drift  set  is  that  if  the  head  timberman 
and  shift-bosses  fail  to  keep  close  watch  of  the  sets,  before  it  is  discovered  the 


Filled  Stope 


—_ —       16  x  J4  Carrier 


20"  Block  20"Block— 

Cap  14"  x  14 


sssssSS^ssS^^ss^fis^^j 

FIG.    69. — DRIFT   TIMBERS   AT   KENNEDY   MINE,    CALIF. 

ground  is  liable  to  have  moved  in  to  the  post  and  broken  the  timbers.  To  guard 
against  this  the  finger-pin  method  was  combined  at  the  Goldfield  Consolidated 
mines  with  the  old  method  of  false  sets.  Then,  in  case  the  sets  are  forgotten 
only  the  timbers  of  the  false  set  will  be  broken. 

It  is  impossible  to  use  these  finger  pins  in  supporting  the  top  lagging  as  ow- 
ing to  unequal  weight  jack-knifing  is  sure  to  occur.  Consequently,  the  pro- 
cedure is  to  carry  the  roof  lagging  on  false  caps  resting  on  blocks  over  the  tops 
of  the  posts,  but  where  old  mine  rails  are  obtainable,  they  probably  make  the 


DRIVING  ADITS  AND  DRIFTS 


119 


best  lagging  for  the  roof  in  swelling  ground.  The  rails  are  used  with  the  bottoms 
against  the  caps.  -  Then  the  ground  as  it  swells  will  force  itself  down  between 
the  rails.  This  is  the  method  used  at  the  Copper  Queen  mines  in  supporting  the 
roof  of  drifts  in  badly  swelling  ground.  Rails  are  also  used  for  side  lagging  in 
the  worst  ground. 


10  z  10-in. 


FIG.    70. — BRIDGE   SETS    WITH   LAGGING    OVER   FINGER   PLNS. 

In  case  the  ground  in  the  bottom  of  a  drift  swells,  the  best  thing  to  do 
is  to  keep  the  bottom  covered  with  several  inches  of  standing  water  or  sand. 
This  keeps  the  air  away  from  the  ground  and  prevents  further  oxidation  of  the 
decomposing  minerals,  generally  the  feldspar.  The  oxidation  of  certain  min- 
erals in  the  rock  is,  in  general,  the  cause  of  swelling  ground.  In  holding  swelling 
ground,  therefore,  the  plan  is  to  ease  the  timbers  as  little  as  possible  each  time 
so  as  to  try  to  get  a  considerable  layer  of  thoroughly  oxidized  ground  exposed 
to  the  air  so  that  further  oxidation  behind  the  outer  layer  will  be  prevented. 

Joint  for  Drift  Timbers.— The  joint  for  framing  the  legs  into  the  cap  of  a 
three-  or  four-piece  drift  set.  shown  in  Fig.  71,  is  designed  to  give  equal  areas  on 


FIG.    71. — AN    IMPRACTICABLE   JOINT. 


the  ends  of  both  cap  and  legs  to  resist  both  downward  and  side  pressures.  This 
joint  would  meet  the  requirements  if  it  could  be  cut  perfectly.  It  is  in  practice 
almost  impossible  to  cut  this  joint  so  that  all  areas  of  the  cut  in  the  cap  will 
bear  evenly  on  all  corresponding  areas  in  the  leg  cut.  For  this  reason  the  joint 
is  not  favored  by  experienced  timbermen.  A  simpler  and  more  effective  joint 


120  HANDBOOK  OF  MINING  DETAILS 

can  be  made  by  bringing  the  ends  of  the  legs  to  bear  under  the  end  o  the  cap 
in  which  no  notch  at  all  is  cut,  then  to  the  under  side  of  the  cap  a  piece  of 
timber  is  spiked,  the  ends  of  which  bear  against  the  upper  ends  of  the  legs  imme- 
diately below  the  cap.  This  piece  of  timber  resists  the  side  pressure  exerted 
against  the  legs,  the  cap,  in  so  far  as  side  pressure  is  involved,  serving  only  to 
carry  this  piece  of  timber.  The  joint  shown  in  Fig.  71  is  liable  to  result  in 
splitting  of  the  timbers  in  those  places  where  the  wavy  shade  lines  are  drawn. 


VI 

STOPING 

Variations  of  Practice— Timbering— Ore  Chutes. 

VARIATIONS  OF  PRACTICE 

Stoping  with  the  Slicing  System. — The  slicing  system  of  stoping  is  being 
carried  on  at  a  number  of  the  Utah  mines  where  the  ground  is  too  heavy  to  be 
held  by  square  sets.  At  the  Daly  West,  Park  City,  and  the  United  States 
mines,  Bingham  Canon,  this  method  is  being  successfully  employed.  The 
practice  is  simply  to  raise  to  the  upper  limits  of  the  ore  and  mine  over  the 
whole  orebody  for  a  thickness  of  one  timber  set,  using  such  timbering  as  is 
necessary  to  hold  the  back.  The  floor  is  then  covered  with  cheap  planking, 
lagging  or  any  available  lumber  which  will  serve  as  a  floor.  Auger  holes  are 
bored  in  the  timbers  holding  the  roof,  loaded  and  the  timbers  shot  down, 
whereupon  the  back  caves  upon  the  flooring  which  has  been  laid.  Another 
"slice"  is  then  worked  out  in  the  same  manner  from  the  raise,  one  set  below 
the  portion  previously  extracted.  To  insure  greater  safety  for  the  men  the  ore 
of  the  successive  slices  is  best  mined  retreating;  i.e.,  a  crosscut  is  driven  from 
the  raise  to  the  other  wall  of  the  orebody,  drifts  run  to  the  stope  limits  and  the 
working  face  advanced  toward  the  raise.  A  safe  retreat  through  the  crosscut, 
which  is  in  solid  ground  and  should  be  well  timbered,  is  thus  always  available 
for  the  miners.  By  this  method  of  stoping  all  the  timber  used  to  hold  the  roof 
as  well  as  the  different  floors  is,  of  course,  lost.  However,  as  the  stopes  need 
not  be  held  open  for  any  length  of  time,  cheap  lumber  may  be  used  for  this 
purpose.  Lumber  in  Bingham  Canon  costs  about  $18  per  thousand  for  local 
Uintah  pine,  and  up  to  $22  per  thousand  for  Oregon  pine.  In  one  of  the  large 
mines  at  Bingham,  where  ore  is  mined  at  about  $1.90  per  ton,  using  square  sets 
in  overhand  stopes,  the  timber  cost  approximates  17  to  34  cents  per  ton  of  ore 
stoped.  Under  the  slicing  system  the  timber  cost  is  probably  not  more  than 
5  cents  per  ton  higher,  and  by  it  ground  is  worked  which  could  hardly  be  held 
by  ordinary  square  setting. 

Stoping  at  Goldfield  Consolidated. — On  the  goo-ft.  level  of  the  Clermont 
mine  of  the  Goldfield  Consolidated  the  Clermont  stope  is  opened  for  about  150 
ft.  on  the  strike  of  the  vein  and  shows  a  width  averaging  40  ft.  On  account  of 
its  high  grade,  all  of  the  ore  must  be  recovered  but  it  is  desirable  to  use  the 
minimum  amount  of  timber.  Under  the  present  stope  practice,  introduced  by 
J.  Donnelly,  mine  superintendent,  8X8-in.  material  is  used  for  the  square  sets 

121 


122 


HANDBOOK  OF  MINING  DETAILS 


and  no  trouble  has  been  experienced  from  the  timbers  swinging.     Square  sets 
and  waste  filling  are  used. 

The  orebody  is  opened  in  sections  eight  sets  long,  and  at  each  eighth  set  a 
manway  is  maintained.  Every  fourth  set  is  used  as  a  chute.  The  stope  is 
filled  with  waste  obtained  from  hanging-wrall  crosscuts,  filling  being  kept  up  to 
the  second  floor  below  the  back  of  the  stope.  Sill  sets  are  8  ft.  in  the  clear  and 
are  framed  of  ioXio-in.  material,  but  the  stope  is  carried  up  with  8X8-in. 
timbers,  the  sets  being  7  ft.  high.  The  end  set  of  each  section  of  stope  is  left 
open  so  that  there  will  be  no  danger  of  filling  crowding  in  and  wrecking  the 
manways.  Where  necessary,  cribbing  is  resorted  to  for  confining  the  filling. 
By  working  the  orebody  in  such  short  sections  the  danger  from  timbers  swinging 
is  eliminated  and  it  is  possible  to  work  successive  sections  instead  of  alternate 
ones  as  must  often  be  done. 

A  Modified  System  of  Back  Stoping  (By  J.  E.  Wilson).— The  general 
scheme  of  a  simple,  safe  and  economical  method  of  stoping  where  the  cost  of 


<",V?|^ 

Broken  Ore 
Reserve 


Chute  Manway 

FIG.    72. — SCHEME    OF   BACK   STOPING   EMPLOYED   AT   THE   DOLORES   MINE. 

labor  and  timber  is  a  serious  consideration  is  shown  in  Fig.  72.  The  method  is 
a  modification  of  back  stoping.  For  the  introduction  of  the  modified  stoping 
it  is  only  necessary  to  drive  one  or  two  raises  at  an  angle  of  45°,  or  less,  depending 
on  the  dampness  of  the  ore  to  be  mined.  Where  the  ore  is  dry  the  raises  may 
be  driven  at  a  flatter  angle.  Stoping  can  be  started  as  soon  as  the  raises  are 
advanced  about  20  ft.  Work  should  begin  above  the  chute,  care  being  taken 
to  cover  the  latter  so  as  not  to  destroy  timbers  while  the  first  few  rounds  are  being 
blasted.  The  first  bench  or  step  mined  will  be  slightly  wider  than  the  chute  and 
manway  combined  and  the  length  will  increase  as  the  stope  advances,  thus 
gaining  stoping  back  for  every  foot  raised.  The  broken-ore  reserve  will  start 
from  the  first  set  of  lagging  put  in,  as  only  the  overflow  will  go  into  the  chute. 
The  filling  of  ore  serves  for  miners  to  stand  upon  while  drilling  the  back. 


STOPING 


123 


The  most  advantageous  method  of  breaking  ground,  according  to  my 
experience,  is  the  bench  or  step  system,  which  is  illustrated  in  the  sketch.  This 
system  eliminates  the  common  and  serious  trouble  of  the  cut  or  "relief"  hole 
failing  to  discharge  and  thus  impairing  the  result  of  the  entire  round.  This 
failure  of  a  round  to  break  the  rock  properly  means  much  added  expense,  is 
quite  annoying,  and  worst  of  all,  exceedingly  dangerous  as  the  following  shift 
may  accidentally  pick  or  drill  into  the  missed  hole;  this  has  often  occurred  with 
disastrous  results. 

The  main  features  in  this  method  of  mining  are  the  elimination  of  shovelers, 
as  all  ore  broken  will  run  into  the  chute  by  gravity,  and  of  expensive  scaffolding. 
No  timber  is  needed,  except  that  for  the  manway  and  chute,  thus  reducing 
expenses  to  a  minimum.  When  the  stope  is  mined  to  the  level  above  the 
process  of  drawing,  the  reserve  ore  can  be  started  either  from  the  top  or  lower 
set  of  lagging,  as  the  case  may  be.  I  would  recommend,  though,  to  draw  from 
the  top,  as  all  boulders  can  beTbroken  before  entering  the  chute.  I  am  now 
using  this  method  in  the  Dolores  mine,  in  Chihuahua,  with  satisfactory  results. 

Eliminating  Shoveling  in  Square -set  Stopes. — It  is  generally  agreed  that 
the  shovel  is  the  most  uneconomic  implement  used  about  a  mine.  The  ideal 


FIG.    73. — SECTION    OF   STOPE    SHOWING   DIVERTING   WING   CHUTES. 


method  of  mining  is  that  which  necessitates  the  least  possible  handling  or 
shoveling  of  the  ore.  An  excessive  amount  of  shoveling,  and  carrying  of  ore  to 
chutes  in  small  wheelbarrows,  is  done  in  most  mines  where  square-set  stoping  is 
practised.  At  the  Argonaut  mine,  Jackson,  Amador  county,  Calif.,  this  is 
eliminated  in  the  stopes  to  a  large  extent  by  building  plank  wings  between  the 
timbers,  which  serve  to  divert  the  ore  to  chutes  as  it  is  broken.  Every  fifth  set 
is  usually  maintained  as  an  ore  chute  so  that  the  wings  need  not  span  more  than 
two  timber  sets  (see  Fig.  73).  This  makes  it  possible  to  keep  the  waste  filling 


124 


HANDBOOK  OF  MINING  DETAILS 


up  to  at  least  the  second  floor  below  that  on  which  the  men  are  working,  an  im- 
portant consideration  in  the  heavy  ground  encountered  on  the  Mother  Lode. 

The  wings  are  merely  temporary  sloping  floors  laid  from  one  cap  to  the  next 
above  or  below  on  either  side  along  the  stope,  and  extending  to  the  ore  chute. 
The  men  work  on  a  few  plank  laid  horizontally  over  the  caps  of  the  topmost 
timber  set,  but  instead  of  breaking  ore  down  on  a  tight  floor  below  and  then 
shoveling  and  wheeling  it  to  chutes  it  is  broken  on  the  wings  which  divert  it  to 
chutes  without  more  labor.  Varying  and  unusual  conditions  in  the  stopes  make 
it  necessary,  of  course,  to  do  some  shoveling  but  the  men  are  required  to  reduce 
this  to  a  minimum. 

In  easily  mined  ground  where  little  shooting  is  required  and  sorting  in  the 
stopes  is  not  advantageous  this  system  works  admirably.  The  saving  effected  by 
eliminating  much  shoveling  and  handling  of  rock  in  the  stopes  doubtless  makes 
it  possible  to  mine  profitably  ore  which,  under  the  old  system  of  mining,  had  to 
be  left.  This  scheme  was  introduced  at  the  Argonaut  by  R.  S.  Rainsford, 
superintendent. 

Recovering  Ore  from  Pillars. — The  accompanying  sketch,  Fig.  74,  illus- 
trates in  plan  and  section  a  method  of  robbing  pillars  at  a  mine  in  the  Joplin 


— l~  Section 

FIG.    74. — ROBBING    ORE   PILLARS. 

district.  The  ore  occurred  in  a  pocket,  where  the  roof  was  heavy  and  a  large 
amount  of  timber  had  to  be  used  to  enable  even  half  the  ore  to  be  extracted. 
The  pillars  themselves  contained  a  high  percentage  of  ore.  Beneath  the  body 
was  a  solid,  compact  limestone  stratum.  The  shaft  was  sunk  a  few  feet  into 
this,  and  a  subdrift  extended  beneath  the  ore  pillars  with  a  7-  or  8-ft.  roof.  A 
raise  was  put  up  in  the  center  of  each  pillar  and  the  ore  shot  down  into  the  drift 
below,  and  trammed  to  the  shaft.  This  method  gave  a  safe  place  in  which  to 
work  and  at  the  same  time  allowed  nearly  all  the  ore  to  be  recovered. 

Scaffolding  for  Drills  in  Wide  Stopes. — In  stoping  in  a  wide  vein  it  is 
often  the  case,  when  an  overhand  stoping  system  is  in  use,  that  some  provision 


STOPING 


125 


must  be  made  for  mounting  the  machine  drills.  If  a  shrinkage  system  of  stop- 
ing  is  being  used,  it  may  also  happen  that  so  much  ore  has  been  drawn  from  the 
stope  that  the  height  of  broken  ore  in  the  stope  is  not  sufficient  to  enable  the 
miner  to  reach  the  back.  In  some  of  the  Lake  Superior  copper  mines  and  in 
certain  mines  of  the  Transvaal,  long  drill  columns  are  used  some  of  which  have 
a  length  of  28  or  32  ft.  It  is  not  always  convenient  to  keep  such  long  columns 
on  hand  or  the  slope  of  the  stope  may  be  such  as  to  make  the  use  of  such  col- 
umns impossible. 

The  accompanying  drawing,  Fig.  75,  illustrates  a  type  of  scaffolding  that  is 
much  used  in  the  wide  stopes  of  some  of  the  mines  of  Western  Australia.  This 
scaffolding  is  built  up  of  vertical  posts  E  well  footed  and  wedged  in  place  at  the 
top.  At  the  required  height  steel  dogs  A  are  driven  into  holes  cut  in  the  backs 


,2  x8-in.  Flooring 


Post 

Plan.  Elevation. 

FIG.    75. — STAGE   FOR   DRILLING    OR   SAMPLING   IN   STOPES. 

of  the  posts.  Through  a  hole  in  the  backs  of  these  dogs,  pass  the  ring-hooks  B, 
made  of  7/8-in.  round  iron.  The  hooks  for  the  end  posts  are  curved  back  as 
shown  at  C,  while  those  between  the  end  posts  are  curved  as  shown  at  D.  The 
dog  holds  the  ring  part  of  the  hook  from  slipping,  but  most  of  the  holding  power 
of  the  hook  is  due  to  binding  against  the  vertical  post.  Horizontal  members 
F  are  carried  in  the  hooks,  and  form  the  support  for  G  the  plank  flooring.  Such 
a  staging  can  be  used  for  a  variety  of  purposes  about  a  mine  besides  that  of 
supplying  a  stage  for  drilling.  In  sampling  high  backs  a  scaffold  can  be  rigged 
with  four  posts  set  at  the  corners  of  a  square  with  four  horizontal  members  form- 
ing the  sides  of  a  square,  that  will  give  easy  and  safe  access  to  the  face  to  be 
sampled. 

Placing  Holes  in  Breast  Stoping  (By  Harvey  S.  Brown).— In  stopes  30 
ft.  or  more  in  width,  breast  stoping  usually  leaves  a  stronger  and  safer  back 
than  back  stoping  by  "upper"  holes.  In  breast  stoping,  the  manner  of  pointing 
the  holes  has  a  definite  influence  on  the  condition  of  the  back.  Holes  drilled 
approximately  at  right  angles  to  the  breast,  i.e.,  parallel  with  the  general 
direction  of  the  advance,  shake  the  back  the  least  and  are,  therefore,  the  most 
desirable.  Holes  drilled  parallel  to  the  breast  cause  loosening  of  the  back, 
necessitating  more  barring  down,  with  attendant  delays.  The  work  can  easily 
be  arranged  so  as  to  permit  pointing  all  the  holes  at  right  angles  to  the  breast. 

A  Method  of  Blasting  in  Stopes. — The  method  of  drilling  and  blasting 


126 


HANDBOOK  OF  MINING  DETAILS 


used  in  many  shrinkage  stopes  of  California  is  worthy  of  far  wider  application 
than  it  receives.  It  can  be  employed  in  any  stope  where  the  muck  from  one 
round  of  holes  is  not  depended  upon  to  furnish  a  foundation  for  the  bar  or  column 
for  the  next  round.  It  may  be  used  in  either  wide  or  narrow  stopes.  Only 
the  rows  of  holes,  a  b  c  in  Fig.  76,  are  blasted  at  one  time,  the  remainder  being 
left  until  the  next  shift.  Thus  the  machine  is  always  well  behind  the  shots  and 
need  only  be  removed  when  all  the  holes  possible  from  the  set-up  have  been 
drilled.  The  troublesome  and  useless  labor  of  carrying  the  drill  and  rig  over 
timbers  and  muck  in  search  of  a  safe  place  to  leave  it,  every  time  a  round  is 
blasted,  is  avoided. 


r 

FIG.    76. — ARRANGEMENT    OF  HOLES    FOR   BLASTING    WITHOUT    REMOVING   DRILL. 

Obtaining  Cheap  Stope  Filling. — A  unique  and  satisfactory  method  of 
obtaining  cheap  waste  for  stope-filling  purposes  is  being  used  on  one  of  the  lower 
levels  of  the  Tramway  mine,  at  Butte,  Mont.  It  is  on  somewhat  the  same 
principle  as  the  glory-hole  method.  Three  crosscuts,  converging  like  fingers 
on  an  open  hand,  were  driven  into  the  granite  country  rock  for  distances  of 
100  ft.  or  more,  and  chutes,  for  drawing  the  waste  out  into  mine  cars,  were 
spaced  along  the  crosscuts  at  regular  intervals.  The  first  floors  over  the  cross- 
cuts were  then  stoped  out,  after  which  the  ground  was  allowed  to  cave,  and  as 
fast  as  the  rock  came  down,  it  was  drawn  out  into  cars.  Filling  to  the  amount 
of  30,000  mine  cars  has  been  taken  out  in  this  fashion  at  a  low  cost. 

"Sand  Filling"  Stopes  in  the  Transvaal.— The  "sand  filling"  process  of 
charging  the  worked-out  stopes  is  being  put  into  operation  at  several  mines  on 
the  Rand,  where  are  prospects  that  in  the  immediate  future  it  will  be  extensively 
adopted.  The  mill  tailings  supply  exactly  the  class  of  material  required.  They 


STOPING  127 

are  handy  and  enable  the  filling  to  be  done  in  a  cheap  and  efficient  manner.  An 
ordinary  pack  of  large  material,  waste  rock,  is  built  next  to  the  level,  backed  by 
smaller  material  against  which  the  water-carried  tailings  are  deposited  until  they 
completely  fill  the  stope.  The  water  drains  off  and  is  pumped  to  the  surface 
to  be  used  over  and  over  again.  Under  favorable  conditions,  it  is  estimated  that 
the  tailings  can  be  deposited  in  the  mine  for  less  than  2d.  per  ton.  In  a  short 
time  the  filling  becomes  solidified  and  is  capable  of  steadying  the  subsidence  of 
the  hanging  wall. 

The  Use  of  Cyanide  Tailings  for  Stope  Fillings. — In  West  Australia 
fatalities  from  the  vitiation  of  the  air  of  mines  by  the  fumes  arising  from  the 
tailings  from  cyanide  treatment  used  for  filling  stoped  ground  have  been  re- 
ported. In  such  cases  it  appears  that  wet,  fresh  tailings  have  been  run  directly 
into  the  mine  without  any  previous  exposure  to  the  air  by  heaping  on  the  surface. 
The  West  Australian  Royal  Commission,  in  dealing  with  this  subject,  recom- 
mended that  tailings  should  not  be  used  for  filling:  (i)  In  the  wet  state;  (2) 
when  they  contain  more  than  o.oi  %  cent,  of  their  weight  of  cyanides  calculated 
as  cyanide  of  potassium;  (3)  in  any  part  of  a  mine  where  there  is  not  a 
current  of  air  passing  freely.  The  Australian  method  of  stope  filling  with 
cyanide  tailings  is  a  dry-filling  system,  whereas  a  water-borne  system  by  which 
the  dry  sands  are  sluiced  into  the  empty  stope  and  the  water  drained  off, 
leaving  the  sand  in  a  compact  mass,  is  used  on  the  Rand,  in  the  Robinson 
mine.  The  Transvaal  Mines  Department  arrived  at  the  conclusion  that  a 
solution  containing  prussic  acid  loses  the  latter  rapidly  by  evaporation  into  the 
air.  In  the  case  of  tailings  being  used  for  filling  stopes,  it  is  considered  likely 
that  the  drainage  from  the  sand  containing  cyanide  will  come  into  contact  with 
acid  water  from  the  mines,  and  that  some  prussic  acid  will  be  formed.  The 
Transvaal  Mining  Regulations  Commission  is  therefore  of  the  opinion  that  the 
percentage  of  cyanide  in  tailings  used  should  be  low  and  good  ventilation  should 
be  required.  A  recommendation  is  made  that  the  regulation  of  the  West  Aus- 
tralian commission  in  this  matter  be  adopted,  pending  the  results  of  further 
investigations  to  be  conducted  in  the  Transvaal. 

Mining  Dangerous  Ground  on  theMesabi  Range  (By  B.  M.  Concklin).— 
Some  of  the  simplest  and  most  useful  practices  in  mining  are  occasionally  over- 
looked for  no  other  reason  than  their  simplicity.  It  may,  therefore,  be  interest- 
ing to  note  a  method  of  mining  practised  on  the  iron  ranges  of  the  Lake  Superior 
region,  which  is  simple  in  itself  and  also  affords  protection  to  the  miners.  In 
this  case  the  ore  is  capped  by  tough  taconite  and  paint  rock,  both  of  which  are 
more  or  less  disintegrated,  while  the  bottom  of  the  orebody  is  solid  taconite. 
The  orebody  is  from  1 8  to  24  ft.  thick.  The  square-set  method  is  usually  used 
in  the  extraction  of  this  ore,  the  orebody  being  too  thick  to  be  adaptable  to  the 
slicing  method  operated  from  one  level  and  too  thin  to  develop  more  than  one 
level. 

In  the  extraction  of  ore  at  the  start  of  operations  the  back  refuses  to  cave 


128 


HANDBOOK  OF  MINING  DETAILS 


entirely,  but  arches  for  considerable  distances,  making  it  extremely  dangerous 
to  the  miners  working  along  the  semi-caved  area.  To  protect  the  workmen 
and  also  to  extend  and  weaken  the  arch  which  holds  the  ground  from  caving 
properly,  square-setting  is  started  two  or  three  sets  back  from  the  semi-caved 
ground.  The  work  is  then  carried  on  just  as  if  a  new  pillar  were  to  be  worked 
out.  The  slice  or  drift  is  first  driven  the  full  width  of  the  pillar;  then  square- 
setting  is  started  toward  the  open  room.  When  the  room  is  reached,  square- 
setting  is  carried  on  from  the  slice  drift  or  crosscut  to  the  open  room  until  the 


\ 

Caved  ground  with 
hanqinqback 

&~" 

**£$* 



„_.. 





—Or^ 

Ore  pillar  fc 
protection  i 
Yforknu 

r 
if 

n 

Tram  way 

Section  A-B 
FIG.    77. — A   SYSTEM    OF   MINING    ON   MESABI   RANGE. 

tramway  is  reached,  when  the  timbers  supporting  the  square  set  room  are  shot 
down  and  the  ground  allowed  to  cave.  This  process  is  repeated  until  the  ground 
caves  satisfactorily,  when  the  square-setting  is  again  resumed,  this  time  imme- 
diately along  the  caved  ground.  The  process  is  illustrated  in  Fig.  77. 

There  seems  to  be  one  serious  objection  to  this  method,  the  probable  loss  of 
ore  in  the  last  pillar  between  the  square-set  room  and  the  tramway,  due  to  the 
fact  that  the  extension  and  resultant  weakening  of  the  arch  has  a  tendency  to 
crush  this  pillar  as  the  timbers  and  pillar  take  weight.  This  disadvantage,  and 
the  additional  cost  of  mining  due  to  driving  the  crosscut  through  solid  ore  across 
the  pillar,  is  offset  by  the  greater  protection  afforded  the  miners. 

Method  of  Rigging  Ladders  to  Reach  Stope  Backs. — In  the  large  under- 
hand stopes  in  the  Tennessee  Copper  Co.'s  mines,  where  the  miners  practically 
never  see  the  back,  which  in  an  open  stope  is  frequently  from  70  to  80  ft.  above 


STOPING 


129 


them,  it  is  evidently  necessary  to  keep  the  roof  well  trimmed  of  all  heavy,  or 
"balk  ground."  To  insure  this,  a  crew  of  men  is  continually  kept  at  work, 
looking  after  the  condition  of  the  roof.  This  work  is  extremely  dangerous  and 
ready  resource  is  required  to  enable  the  men  to  gain  access  to  the  back.  Fig.  78 
shows  the  method  of  rigging  ladders  to  reach  the  roof  over  the  benches  of  an 
underhand  stope,  open  to  its  full  height  and  for  a  width  of  from  50  to  150  ft. 
The  ladders  are  securely  lashed  together,  and,  as  shown,  stayed  by  ropes  secured 
to  the  drill  steels  set  into  the  rock  face.  A  small  stoping  drill  is  frequently  slung 
from  the  ladder  and  used  to  put  holes  in  the  roof  where  much  balk  ground  must 
be  slabbed  down.  Shooting  the  roof  is,  however,  a  dangerous  practice,  as 
shattered  rock  is  apt  to  be  left  to  fall  later,  when  the  face  of  the  stope  has  ad- 
vanced and  the  back  is  inaccessible. 


FIG.  78. — LADDER  SCAFFOLD  FOR  STOPES.  . 

Staging  for  High  Set-ups  in  Stopes. — In  stoping  the  flat-dipping  veins  of 
the  Lake  Superior  copper  mines,  machine-drill  posts  10  and  12  ft.  long  are  some- 
times used.  When  top  holes  are  being  drilled  some  staging  must  be  used  upon 
which  the  drill  runners  may  stand.  This  staging  is  often  made  in  the  following 
way:  At  a  point  a  little  farther  from  the  face  than  the  drill  post,  a  piece  of  drill 
steel  or  better  a  piece  of  2-in.  pipe,  approximately  as  long  as  the  drift  is  high,  is 
wedged  between  the  hanging  and  foot  wall  in  a  vertical  position.  A  second  up- 
right is  placed  in  a  similar  position  to  one  side  of  the  other,  so  that  a  line  between 
the  two  is  approximately  parallel  to  the  breast  of  ore.  A  chain  is  then  bound 
around  each  in  a  series  of  half  hitches  and  a  clove  hitch  at  a  height  above  the 
9 


130  HANDBOOK  OF  MINING  DETAILS 

floor  a  little  greater  than  the  height  of  the  platform  on  which  the  operator  desires 
to  stand.  A  piece  of  drill  steel  or  pipe,  a  few  feet  greater  in  length  than  the  dis- 
tance of  the  upright  from  the  breast,  is  then  slipped  horizontally  between  two  of 
the  half  hitches  in  the  chain,  until  the  end  rests  on  a  projection  or  in  a  hitch  in 
the  breast.  One  end  of  this  horizontal  pipe  is  supported  by  the  hitch,  the  other 
by  the  chain.  If  properly  hitched  the  chain  will  not  slip  down  the  upright  pipes. 
One  such  horizontal  pipe  is  supported  by  each  upright.  The  platform  is  made 
by  placing  two  horizontal  planks  so  as  to  rest  across  the  two  horizontal  pieces  of 
pipe;  one  in  front,  the  other  in  back  of  the  drill  posts.  On  these  planks  the 
operators  stand  while  drilling  the  upper  holes.  The  advantage  of  this  staging 
is  that  it  is  secure,  light,  quickly  erected,  and  can  be  adjusted  to  different  heights 
by  slipping  the  chains  up  and  down  on  the  uprights. 

Chain  Ladders  in  Waste  Chute. — In  the  Utica  mine,  at  Angel's  Camp, 
Calif.,  waste  is  dumped  into  the  stopes  through  raises  from  above.  When  an 
entrance  to  the  stope  is  desired,  chain  ladders  are  used  in  the  waste  chutes. 
The  ladders  are  built  by  connecting  two  chains  with  round  iron  rods  at  proper 
intervals.  The  connections  are  made  by  simply  passing  the  ends  of  the  rods 
through  links  of  the  chains  and  bending  the  rods  back  so  as  to  have  either  end 
of  each  rod  linked  to  a  chain.  Such  ladders  are  practically  indestructible  even 
when  used  in  chutes  through  which  waste  is  constantly  being  passed. 

TIMBERING 

Notes  on  Placing  and  Cutting  Stulls. — The  hitch  bottom  should  be  level 
and  not  less  than  2  in.  in  depth,  and  the  back  edge  should  be  at  right  angles  to 
the  line  of  the  stull  or  as  nearly  so  as  possible.  For  a  heading,  it  is  sufficient  to 
merely  smooth  off  the  face  of  the  rock  so  as  to  enable  a  good  fit  to  be  secured, 
no  bottom  or  sides  being  necessary.  A  vertical  bevel  of  from  10  to  20°  will  hold 
the  stull  firmly  in  place. 

To  measure  and  cut  a  stull,  it  is  well  to  have  a  slidestaff  and  try-square,  but 
a  good  fit  can  be  made  with  a  tape  alone.  Referring  to  Fig.  79,  the  tape  is  held 
at  a  and  a-b  is  measured.  Point  c  is  next  established  vertically  above  b  and  at  a 
distance  from  it  equal  to  the  thickness  of  the  proposed  timber,  and  a-c  is  meas- 
ured. These  are  all  the  measurements  required  if  the  hitch  and  heading  are 
square.  The  wall  above  c  must  be  cleared  of  projections  that  would  interfere 
with  dropping  the  stull  into  place  along  the  arc  c-x.  The  bevel  of  the  butt  of 
the  stull  (the  angle  b-a-d)  may  be  estimated  by  the  eye.  The  butt  of  the  stull 
is  sawed  first  along  the  line  d-a  making  the  plane  d-p-a-o  and  the  long  corner  is 
lopped  off  with  an  axe  making  the  plane  s-a-o-p,  and  the  edge  o-p  square  with 
the  line  of  timber.  Then  the  sides  are  trimmed  as  shown  making  o-p  equal  to 
the  width  of  the  hitch.  With  the  tape  held  at  o  or  p,  using  the  measurements 
a-b  and  a-c,  the  points  b  and  c  are  marked  on  bottom  and  top  of  the  timber 
allowing  slightly  for  the  bend  in  the  tape  caused  by  the  partial  wrapping  around 
the  stull. 


STOPING  131 

It  is  frequently  necessary  to  set  a  stull  where  neither  hitch  nor  heading  can 
be  made  square  with  the  line  of  the  timber.  On  the  heading  a  circle  is  marked 
in  some  manner  to  represent  approximately  the  outline  of  the  stull.  Referring 
to  Fig.  80,  point  a  is  the  back  center  of  hitch  bottom,  and  o  and  p  the  corners; 
b,  c,  n,  and  m  are  respectively  the  bottom,  top,  and  sides  of  the  circle  marked  on 
the  heading ;  a-b,  b-o,  b-p,  n-o,  and  m-p  are  measured.  The  face  s-o-p-a,  is  first 
made  by  a  cut  with  the  axe  and  a  mark  made  on  this  to  represent  point  a. 


Plan 


Plan 


FIG.    79. — METHOD   OF  MEASURING   THE   STULL. 

A-b  is  then  measured  and  b  marked;  o  and  p  are  located  equidistant  from  a  by 
the  measurements  b-p  and  b-o  from  point  b,  care  being  taken  that  o-p  is  equal  to 
width  of  hitch.  The  face  d-o-p  is  sawed  and  the  sides  trimmed;  o^n  and  p-m 
are  laid  off  and  the  head  is  sawed  through  the  points  b,  m,  and  n.  Additional 
measurements  to  c  may  be  made  as  a  check.  A  stull  of  this  kind  should  be 
braced  laterally  by  a  collar  brace  to  the  next  timber. 

Wedging  must  be  done  at  the  butt.  The  head  should  fit  snugly  against  the 
rock  at  all  points  but  especially  at  the  bottom.  Wedges  driven  at  the  head  are 
a  sign  of  poor  work. 

The  saddleback  system  of  timbering  consists  of  the  use  of  two  ordinary  stulls 


132  HANDBOOK  OF  MINING  DETAILS 

with  their  heads  meeting  upon  the  opposite  sides  of  a  2 -in.  board  so  as  to  form 
an  arch.  It  is  used  occasionally  where  the  drive  or  stope  is  too  wide  to  allow 
the  use  of  a  single  stull. 

Framing  of  Round  Timbers  (By  Percy  E.  Barbour).— The  application  of 
square- timber  framing  methods  to  round  timbers  is  illustrated  in  Fig.  81.  In 
the  upper  drawing  is  shown  in  detail  a  square-set  framed  joint,  assembled. 
However,  when  it  is  wished  to  produce  a  similar  joint  with  the  use  of  round 
timbers,  the  problem  becomes  a  little  more  complicated.  The  lower  drawing 
shows  all  the  details  necessary  to  prepare  round  timbers  for  this  sort  of  joint. 
It  will  be  noticed  that,  whereas  with  the  square  timbers  there  is  but  one  bearing 


FIG.   80. — THE   STULL  IN  PLACE. 

surface  at  the  end  of  a  given  piece,  as  at  A  ;  in  the  case  of  the  round  timber  fram- 
ing there  are  two  bearing  surfaces,  as  at  B  and  C. 

Leaning  Stope  Sets. — In  the  Argonaut  mine  at  Jackson,  Calif.,  and  to  a 
less  extent  in  some  of  the  other  Mother  Lode  mines,  leaning  sets  replace  the 
usual  square  sets  in  stopes  up  to  a  width  of  16  ft.,  which  is  the  full  length  of  the 
ordinary  stull.  The  advantage  of  the  leaning  over  the  square  set  is  in  the  fact 
that  posts  can  always  be  set  directly  above  each  other.  In  the  Argonaut  the 
veins  dip  at  such  an  angle  that  it  is  almost  impossible  to  get  in  square  sets  so  as 
to  have  posts  rest  on  posts  in  the  short  space  of  time  that  the  ground  will  hold. 
Simple  stull  timbering  without  posts  would  not  hold  the  walls,  which  are  blocky 
and  in  many  cases  must  be  lagged. 

The  so-called  leaning  sets  are  really  stull  timbering  with  posts  and  girts 
added.  Or,  from  a  different  viewpoint,  square  sets  of  variable  width,  placed 


STOPING 


133 


with  the  posts  parallel  to  the  walls  of  the  orebody  instead  of  vertical.  The 
standard  sets  are  framed  of  8-ft.  posts  and  caps  and  4-ft.  sprags  or  girts.  Round 
stull  timber  is  generally  used.  The  greatest  amount  of  pressure  is  from  the 
swelling  of  the  walls,  and  to  take  up  this  the  posts  are  usually  given  a  horn  from 
4  to  8  in.  square.  The  sprags  are  not  framed. 


FIG.    8l. — DETAILS   OF   SQUARE   SET  WITH   ROUND   TIMBERS. 


The  usual  method  of  timbering  drifts  below  leaning  sets  is  shown  in  Fig.  82. 
In  general,  two  stringers,  one  on  either  wall,  are  blocked  up  from  the  drift  set 
and  separated  by  a  stull.  They  are  wedged  into  position  and  the  swell  of  the 


134 


HANDBOOK  OF  MINING  DETAILS 


walls  soon  holds  them  so  firmly  that  they  will  support  the  filled  stope  above, 
even  after  the  drift  sets  below  are  removed. 

Battery  Method  of  Stull  Timbering  (By  Claude  T.  Rice).— It  is  generally 
considered  that  stulls  over  12  ft.  in  length  have  little  supporting  power  in  stopes. 
This  is  true  where  the  ordinary  method  of  stull  or  post  timbering  is  used,  but  by 
standing  the  stulls  in  groups,  or  batteries,  as  they  are  called  in  the  Lake  Superior 


FIG.   82. — LEANING   STOPE   SETS   USED    ON  MOTHER  LODE. 

copper  district,  stulls  can  be  made  to  support  heavy  roofs  in  stopes  as  wide  as 
40  ft.  Indeed,  this  form  of  timbering  has  replaced  the  method  of  square-set 
timbering  formerly  used  in  the  Calumet  &  Hecla  mines  in  which  the  caps  were 
parallel  with  and  the  posts  at  right  angles  to  the  lode. 

This  grouping  of  the  stulls  gives  them  much  greater  strength  than  the  same 
area  of  timber  would  have  if  placed  in  one  stull,  while  by  grouping  them,  poorer 
grades  of  timber,  and  smaller  and  therefore  less  expensive  sizes  can  be  used. 
In  the  Calumet  &  Hecla  workings  where  this  form  of  timbering  originated,  and 
where  it  alone  is  used  at  present,  the  battery  consists  of  three  posts  or  stulls. 
Two  are  placed  in  the  line  of  the  strike  and  above  these,  a  somewhat  smaller 
post  that  supports  the  wall  plate  or  cap  that  carries  the  stringers  over  which  the 
lagging  for  the  roof  is  laced.  Round  timber  flattened  at  the  ends  where  it  is  to 
rest  upon  the  posts  of  the  battery  is  used  for  the  wall  plates.  In  case  the  hanging 
wall  is  good  so  that  it  does  not  require  top  lacing  between  the  batteries,  a  block 


STOPING 


135 


is  put  in  between  the  front  leg  and  the  top  blocking  so  that  it  can  be  knocked 
out  and  the  wall  piece  inserted  later  if  necessary.  The  timbers  of  the  battery 
are  stood  directly  on  the  foot  wall,  but  the  top  blocking  over  them  is  interlaced 
so  as  to  tie  the  group  together  at  the  top  when  the  battery  takes  weight.  The 
posts  of  the  batteries  at  the  Calumet  &  Hecla  mines  range  in  diameter  from 
1 6  to  30  in.,  according  to  the  width  of  the  stope  and  the  condition  of  the  hanging 
wall.  These  timbers  are,  therefore,  quite  heavy,  but  they  are  easily  swung  into 
place  by  means  of  a  small  air  hoist  placed  out  of  harm's  way  at  the  bottom  of 
the  stope. 


Wedge 


Block  back  of  Wall  Plate. 

stringer  resting  on  Wall  Platei. 


Head  Block,  8  z  10-in. 


Hoisting  Bope  to 

Air  Hoist  at 
Bottom  ot  Stope 


FIG.  83. — BATTERY  STULLS  IN  CALUMET  &  HECLA  STOPES. 

There  is  a  division  of  function  in  the  different  posts  of  the  battery.  The 
two  main  legs  which  are  put  in  somewhat  larger  than  the  front  leg  carry  most  of 
the  weight  of  the  hanging  wall  and  they  also  resist  the  bending  tendency  in  the 
posts  of  the  battery,  while  the  main  duty  of  the  front  leg  is  to  carry  the  wall  piece 
that  supports  the  scalings  that  come  from  the  roof  later  in  the  life  of  the  stope. 
As  the  top  post  rests  on  the  other  two  posts  of  the  battery,  the  lower  two  help 
take  care  of  bending  strains  that  come  on  the  front  leg.  Consequently,  two 


i36 


HANDBOOK  OF  MINING  DETAILS 


shorter  pieces  of  stull  can  be  put  in,  butt  to  butt  with  a  tying  piece  of  soft  3-in. 
fir  between  them,  to  serve  as  the  front  leg.  This  spliced  stull,  unless  the  hanging 
is  especially  heavy,  serves  almost  as  well  as  a  stull  all  in  one  piece  would,  for  the 
pressure  on  it  is  mainly  longitudinal.  In  this  way  short  pieces  of  stull  that  have 
been  recovered  from  batteries  in  old  stopes  before  they  caved  can  be  used  in  the 
narrower  stopes. 

In  the  conglomerate  stopes  of  the  Calumet  &  Hecla  company  these  batteries 
are  put  in  at  intervals  of  6  ft.  in  the  direction  of  strike  of  the  lode  and  from  6  to 
9  ft.  or  more  apart  on  the  dip,  according  to  the  heaviness  of  the  hanging  wall. 


FIG.    84. — END    VIEW   OF   STOPE,  WALLAROO    MINES. 


After  the  timbering  of  the  stope  is  about  halfway  to  the  level  above,  the  size  of 
the  stulls  used  in  the  batteries  is  reduced  for  it  is  in  the  bottom  half  of  the  stope 
that  the  most  weight  comes.  In  the  Hecla  workings  where  the  stopes  have  a 
width  of  from  14  to  16  ft.  on  an  average  a  gang  of  six  timbermen  can  stand  and 
lace  two  batteries  in  a  nine-hour  shift,  while  in  the  Red  Jacket  workings  where 
the  stopes  vary  in  width  between  16  and  25  ft.  and  have  an  average  width  of 
20  ft.,  and  the  hanging  wall  is  not  generally  as  good  as  in  the  South  Hecla  stopes, 


STOPING 


137 


a  timber  gang  can  only  stand  and  lace  on  an  average  three  batteries  in  two 
shifts. 

The  resistance  of  this  battery  system  against  bending  strains  is  amazing  for 
in  some  parts  of  the  Tamarack  workings  batteries  are  being  used  in  stopes  42 
ft.  wide.  In  such  cases  foot  blocking  as  well  as  head  blocking  is  used,  and  in 
order  to  take  care  of  bending  stresses  the  three  stulls  of  the  battery  are  either 
wound  with  wire  rope  at  their  middle  or  else  braced  halfway  down  by  struts  from 
the  other  batteries.  In  this  way  the  batteries  are  made  to  stand  in  such  stopes 
for  3  or  4  months  before  the  weight  of  the  hanging  wall  becomes  too  great  for 
them. 


l 

FIG.   85. — TIMBERING   NARROW  STOPES   IN  TREACHEROUS   GROUND. 

The  experience  of  the  Calumet  &  Hecla  company  would  seem  to  show  that, 
for  timbering  stopes  where  the  dip  is  flat  and  the  roof  heavy,  the  battery  system 
is  stronger  and  cheaper  than  the  use  of  square  sets  and  rock-filling.  Fig.  83 
illustrates  the  manner  of  placing  the  batteries  of  stulls. 

Timbering  Wide  Stopes. — H.  L.  Hancock,  general  manager  of  the  Walla- 
roo &  Moonta  Mining  &  Smelting  Co.,  South  Australia,  recently  visited  the 
principal  mining  centers  of  the  United  States  in  search  of  information  which  his 
company  might  profitably  utilize  in  the  mining  and  smelting  of  copper  ore.  In 
his  report  Mr.  Hancock  stated  that,  in  his  opinion,  he  observed  no  methods  of 


138  HANDBOOK  OF  MINING  DETAILS 

mining  at  any  mine  visited  which  could  be  substituted  to  advantage  at  the 
Wallaroo  mines. 

The  "stye"  and  filling  system  used  at  the  Wallaroo  mines  is  illustrated  in 
Figs.  84  and  85.  This  method  is  old,  and  is  used  in  securing  treacherous 
ground  in  wide  stoping  widths.  In  some  of  the  old  mines  at  Clunes  and  Edger- 
ton,  where  the  stopes  were  100  ft.  wide  in  places,  firewood  was  used,  as  shown  in 
Fig.  84,  in  building  what  are  called  "horses,"  when  made  of  timber  only,  and 
"pigstyes"  when  an  outer  frame  of  timbers  is  filled  with  waste.  The  latter 
kind  of  support  is,  of  necessity,  much  used  where  mining  timber  is  scarce. 
-Fig.  85  shows  the  system  used  in  timbering  narrow  stopes  in  treacherous  ground, 
when  approaching  a  level.  The  endeavor  is  made  to  dispense  with  "horses" 
or  "styes"  as  much  as  possible  where  it  is  practicable  to  use  filling. 

Placing  Sills  beneath  Square  Sets  Already  in  Place. — The  correct 
practice  in  square-set  timbering  is  to  place  the  sills  upon  the  floor  of  the  stopes 
before  the  sets  are  put  in.  Yet,  through  false  ideas  of  economy,  the  placing  of 
sills  is  frequently  neglected  with  the  results,  when  it  becomes  desirable  to  stope 
the  ore  up  to  the  floor  of  one  level  from  that  next  below,  the  operation  can  only 
be  accomplished  by  catching  up  the  square-set  posts  from  below  at  the  expense 
of  much  time  and  labor. 

On  the  Mother  Lode  of  California  there  are  few  mines  where  sills  are  placed 
on  the  floors  of  the  levels,  it  being  claimed  that  the  sills  will  rot  before  a  stope  is 
worked  through  from  one  level  to  that  next  above.  Owing  to  the  large  sectional 
area  of  most  stopes  in  these  mines  and  to  the  heavy  swelling  ground  commonly 
encountered,  this  statement,  generally  speaking,  is  without  doubt  true.  These 
conditions  might  be  met  by  cutting  stopes  of  smaller  sectional  area,  i.e.,  if  the 
stopes  were  worked  in  sections  extending  from  foot  to  hanging  wall  but  only  for 
30  or  40  ft.  along  the  vein. 

Generally,  however,  the  stope  is  opened  on  the  level  of  the  gangway  to  the 
full  width  of  the  vein  and  for  the  entire  length  of  the  oreshoot,  before  any  con- 
siderable upward  stoping  is  undertaken.  This  practice  in  most  cases  eventually 
results  in  giving  the  mine  management  more  or  less  trouble  later  on,  which  is 
rendered  worse  by  failure  to  provide  sills  on  the  floor  of  the  level,  and  by  the 
failure  to  fill  the  stope  completely  as  work  progresses  upward.  Close  filling  of 
the  stope  is  often  neglected  as  the  waste  rock,  in  most  cases,  has  to  be  broken 
from  the  walls,  and  this  entails  considerable  extra  expense. 

In  many  cases  sills  may  be  inserted  beneath  the  posts  of  the  sets  long  after 
they  have  been  in  place,  and  the  ore  from  the  back  of  the  stope  next  below  re- 
moved with  safety,  and  usually  with  little  loss.  It  is  a  great  advantage  in  con- 
necting levels  to  have  the  timber  sets  in  exact  alignment,  both  longitudinally 
and  transversely  of  the  vein,  on  each  level ;  having  the  posts  stand  immediately 
over  each  other  makes  the  connection  much  less  difficult  and  expensive.  The 
proper  place  for  the  sills  on  each  level  can  be  easily  established  by  the  mine 
surveyor,  and  the  lines  once  given  on  the  level  there  is  no  difficulty  in  the 


STOPING 


139 


timbermen  keeping  the  sets  in  line,  as  all  the  members  of  the  sets  are  of  standard 
length  (or  should  be),  and  consequently  the  sets  of  one  level  conform  to  the 
position  of  those  both  above  and  below. 

When  sills  have  been  omitted  at  the  time  the  stope  was  started  and  the  plac- 
ing of  the  sets  commenced,  and  it  becomes  necessary  to  place  them  later,  this  may 
be  accomplished  by  spragging  the  posts  of  the  sill  floor  as  tightly  as  possible, 
both  longitudinally  and  transversely  of  the  stope,  and  sawing  off  the  foot  of 
each  post  at  the  proper  height  and  slipping  the  sills  beneath.  As  a  matter  of 
course  this  cannot  be  done  in  a  stope  that  has  been  even  partly  filled. 

When  the  stope  is  still  open  and  it  is  desired  to  place  the  sills  as  suggested 
above  it  may  be  accomplished  in  the  following  manner:  The  sills  should  be  laid 
so  as  to  butt  against  each  other  at  the  ends,  or  they  may  be  framed  so  that  the 
ends  will  overlap,  by  cutting  out  the  upper  half  of  one  and  the  lower  half  of  the 


FIG.   86. — TIMBERING  ARRANGEMENT  FOR   REMOVING   BACK. 


other,  which  will  facilitate  in  no  small  degree  the  connection  of  the  stopes.  This 
must  be  done  with  great  care  and  should  not  be  left  to  inexperienced  hands.  The 
work  must  be  done  in  small  sections,  and  begun  only  after  all  the  sills  have 
been  placed  in  position  in  the  stope.  The  sills  should  be  as  long  as  it  is  possible 
to  handle  them — not  less  than  two  sets  long,  and  three  sets  would  be  better. 
They  should  be  placed  across  the  vein,  from  foot  to  hanging  wall,  and  the  tim- 
ber should  be  of  good  size,  as  they  may  be  called  upon  to  sustain  a  greatly  in- 
creased pressure  when  the  stopes  are  connected. 

An  idea  of  the  method  of  placing  sills  in  stopes  where  they  have  been  omitted 
may  be  obtained  from  Fig.  86.  The  same  method  may  be  successfully  applied 
should  it  be  deemed  advisable  to  replace  old  and  rotten  sills  with  new  ones. 


140  HANDBOOK  OF  MINING  DETAILS 

ORE  CHUTES 

Centennial-Eureka  Chute  Pocket  and  Gate.— Hard  silicious  ore  will 
quickly  cut  out  the  bottom  of  almost  any  sort  of  chute  gate  or  inclined  ore  pass. 
The  ore  at  the  Centennial-Eureka  mine,  at  Eureka,  Utah,  is  of  such  a  character 
that  it  will  quickly  cut  through  even  a  double  lagged,  inclined,  bottom  of  an  ore 
chute,  so  a  special  type  of  chute  in  which  a  bed  of  rock  forms  the  bottom  has 
been  devised. 

An  ore  pocket  is  formed  by  building  up  from  the  level  three  sets  of  square 
set  timbers  into  which  ore  from  the  stopes  is  delivered.  Single  2 -in.  lagging  is 
used  to  line  the  bottom  set  of  the  pocket  or  chute,  and  this  set  is  filled  with  waste 
rock.  On  the  side  from  which  the  ore  is  to  be  delivered  to  cars,  the  posts  are 
notched,  the  cap  being  dropped  7  in.  and  placed  with  the  faces  45°  from  the 
horizontal.  A  plank  lip  is  then  nailed  to  the  cap;  this  extends  only  a  short  way 
into  the  pocket,  but  far  enough  into  the  drift  to  deliver  ore  over  the  edge  of  a  car. 
An  ordinary  gate  of  planks  sliding  between  wooden  guide  grooves  is  used  to 
control  the  discharge  of  ore  from  the  pocket.  The  lip  on  some  of  the  Centennial- 
Eureka  chutes  is  35  in.  wide  and  auxiliary  posts  are  placed  under  the  cap  at  either 
side  of  the  lip.  The  top  two  sets  of  the  pockets  are  lined  with  double  2 -in. 
lagging. 

In  this  construction  the  waste  filling  the  bottom  set  of  the  chute  or  pocket 
forms  a  bed  upon  which  the  ore  drops  and  over  which  it  slides  in  its  passage  to 
the  discharge  gate.  The  wear  from  the  movement  of  the  ore  is  all  taken  up  at 
this  point  and  all  trouble  with  the  bottom  of  the  chutes  cutting  through  is  elimi- 
nated as  the  waste  forms  the  bottom.  Owing  to  the  large  cross  section  of  the 
pocket  the  movement  of  ore  is  slow  (if  the  pocket  is  not  entirely  drawn  at  any 
time)  so  the  lagging  in  the  upper  sets  is  not  subjected  to  excessive  wear,  and  in 
fact,  seldom  has  to  be  renewed.  Such  a  chute  pocket  is  about  as  satisfactory 
and  as  near  fool-proof  as  any  to  be  found,  and  it  has  the  additional  advantage 
that  it  can  be  quickly  built  from  the  material  used  for  ordinary  mine  timbering, 
and  hence  usually  in  stock.  As  stated,  this  ore  pocket  and  gate  are  particularly 
useful  for  handling  hard,  silicious  ores. 

Steel  Ore  Chute  for  Use  in  High-grade  Stopes. — When  high-grade  ore 
is  being  mined  it  is  always  advisable  to  exert  every  possible  care  to  see  that 
the  fines,  which  often  run  high  in  gold  and  silver,  are  not  lost.  To  this  end  in 
the  square-set  stopes  of  the  Centennial-Eureka  mine,  at  Eureka,  Utah,  every 
other  floor  is  tightly  boarded  over  so  that  the  fines  cannot  drop  through.  All  ore 
is  handled  to  chutes  on  the  tight  floors.  Steel  ore  chutes  or  passes  are  used 
between  floors  and  to  deliver  ore  to  the  haulage  levels.  Stope  sets  are  7  ft.  4  in., 
center  to  center. 

The  ore  is  broken  down  on  8X  8-in.  shooting  timbers  and  dropped  one  set  to 
a  tight  floor,  there  sorted  and  shoveled,  or  wheeled,  to  the  steel  chutes  into  which 
it  is  dumped.  These  chutes  are  built  in  sections,  that  is,  they  are  carried  from 


STOPING 


141 


one  tight  floor  to  the  stope  floor  immediately  below  on  which  ore  is  broken,  and 
terminate  about  3  ft.  above  the  second  floor,  below  which  is  another  one  that  is 
tightly  boarded.  At  each  tight  floor  a  temporary  wooden  hopper  mouth  is 
built  to  the  chute  so  that  ore  from  above  will  drop  into  the  lower  continuation, 
and  so  that  ore  from  that  stoped  floor  can  be  easily  shoveled  or  dumped  into  it. 
The  chutes  being  in  sections,  can  be  easily  moved  to  another  portion  of  the  mine 
when  one  stope  is  finished.  The  steel  ore  passes  are  14X14  1/2  in.  inside 
measure,  the  sides  being  3/i6-in.  sheet  steel,  bolted  at  the  edges  to  vertically 
placed  i  1/2X1  i/2Xi/4-in.  angles.  By  placing  the  angles  on  the  outside 
corners  they  are  not  subjected  to  any  wear. 

Such  chutes  are  tight  and  durable,  and  their  use  in  conjunction  with  tightly 
boarded  stope  floors  insures  the  delivery  of  all  ores  from  the  stopes.  Such 
refinements  of  practice  (the  additional  costs  thereby  entailed)  are  unwarranted 
in  handling  large  quantities  of  low-grade  rock,  but  with  such  ore  as  is  mined  at 
the  Centennial-Eureka,  the  loss  that  would  result  from  careless  handling  of  the 
ore  through  cribbed  or  loosely  lagged  chutes  would  probably  be  much  greater 
than  is  the  cost  of  extra  installation. 

Bulkheaded  Ore  Chutes. — Ore  chutes  are  carried  up  through  stopes,  in 
many  of  the  mines  on  the  Mother  Lode  of  California,  by  simply  lagging  around 


-co 


FIG.   8*7. — PLAN   OF  BULKHEADED    ORE  CHUTE. 

timber  sets.  No  lining  is  put  inside  of  the  square-set  timbers  in  the  chute. 
This  construction  serves  well  enough  unless  a  rock  happens  to  carry  away  one 
of  the  exposed  horizontal  timbers  in  the  passage  way,  in  which  case  the  light 
lagging  is  quickly  torn  out,  letting  in  waste  and  often  resulting  in  losing  the  chute. 
The  lagging  may  not  hold  the  waste  anyhow  if  the  walls  are  heavy  or  timber  sets 
swing. 

A  type  of  ore  chute  used  in  the  South  Eureka,  near  Sutter  Creek,  Calif.,  is 


142  HANDBOOK  OF  MINING  DETAILS 

far  better  for  heavy  ground  and  large  stopes  where  the  pressure  from  waste 
filling  is  liable  to  be  considerable.  Fig.  87  shows  how  the  chutes  are  built. 
Stull  timbers  flattened  off  on  two  sides  like  ties,  "flats,"  are  first  fitted  in  (across 
the  vein)  between  the  posts.  Across  the  ends  of  these  flats  are  then  laid  poles, 
or  round  timbers,  with  their  ends  extending  to  the  outside  of  the  flats.  The 
poles  are  set  inside  of  and  tangent  to  the  posts.  Alternate  flats  and  poles  are 
then  laid  as  the  stope  progresses.  The  lagging  is  not  put  on  until  filling  com- 
mences, as  ore  can  be  shoveled  between  the  bulkheading  into  the  chute. 

The  advantage  of  this  type  of  chute  is  in  its  durability  and  strengthening 
effect  on  the  stope  timbering.  The  lining  is,  of  course,  strong  and  wears  in 
most  cases  as  long  as  the  stope  lasts.  Also  broken  timbers  can  be  readily  re- 
placed without  danger  of  the  chute  caving.  Then  too  the  flats  reinforce  the 
posts  of  the  chute  set  and  prevent  adjoining  sets  from  swinging.  Thus  instead 
of  being  as  usual  a  weak  place  in  the  stope  timbering,  such  a  chute  acts  as  a 
reinforcement. 

Lining  for  Ore  Chutes. — The  majority  of  mining  companies  usually  line 
the  bins  and  ore  chutes  with  sheet  steel.  It  is  seldom  that  the  steel  sheets  are 
worn  uniformly  and  as  soon  as  a  hole  occurs  it  is  necessary  to  renew  the  entire 
sheet,  which  often  means  a  waste  of  material  and  extra  expense.  At  Mineville, 
N.  Y.,  Witherbee,  Sherman  &  Co.  found  it  more  economical  to  use  bar  steel. 
At  present  they  use  3/4X6-in.  bars.  By  using  bars  it  is  less  trouble  to  do 
repair  work  and  it  is  necessary  to  remove  only  the  worn-out  part  and  put  in  a 
new  piece.  All  the  steel,  even  short  bars  with  one  end  worn  thin,  may  thus  be 
used.  Railroad  rails  of  heavy  weight  are  also  good  for  lining  the  front  of  ore 
bins  at  a  point  directly  opposite  the  place  where  the  cars  dump.  They  are 
occasionally  suspended  by  the  upper  end  and  are  free  to  move  at  the  lower  end. 
They  form  an  excellent  buffer  for  heavy  ore  as  it  comes  from  the  mine  car  or  skip. 

Safeguarding  Ore  Chutes. — Where  winzes,  ore  chutes  or  ore  passes  open 
into  a  floor  of  a  drift  they  are  a  constant  source  of  danger  to  the  miners  and 
trammers  who  have  to  pass  through  the  drift.  In  a  large  mine  there  are  usually 
many  such  openings  in  the  floors  of  the  various  drifts  and  unless  they  are  pro- 
tected in  some  way,  accidents,  such  as  men  falling  into  the  openings,  are  sure  to 
occur. 

It  is  an  excellent  plan  to  cut  all  such  passes  so  that  they  will  open  to  one  side 
of  the  drift  or  into  a  niche  cut  into  one  wall.  In  such  cases  there  need  be  no 
opening  in  the  floor  of  the  drift  itself,  but  it  is  not  always  possible  to  offset  the 
winzes  in  such  a  manner.  Wherever  there  is  an  opening  in  the  floor  of  a  drift 
through  which  miners  pass,  some  provision  should  be  made  so  that  a  man 
cannot  fall  into  it.  Preferably  the  opening  should  be  closed  by  a  gate  or  else 
by  a  rough  grizzly  of  logs  or  timbers.  Where  the  run-of-mine  ore  is  coarse,  it 
may  not  be  possible  to  use  log  grizzlies.  In  such  a  case  some  warning  should  be 
given  the  passer-by  in  order  to  make  him  aware  of  the  fact  that  he  is  approaching 
the  collar  of  a  winze. 


STOPING 


143 


At  the  Ray  Consolidated  mine  in  Arizona  a  device,  similar  to  that  used  on 
railroads  to  warn  trainmen  that  they  are  approaching  a  bridge,  is  employed  at 
all  places  where  there  are  openings  in  the  floor  of  a  drift  into  which  a  man  might 
fall.  The  device  consists  of  a  beam  set  in  the  roof  of  the  drift  about  4  ft.  from 
the  edge  of  the  opening;  one  beam  is  used  on  each  side  of  the  opening.  From 
this  beam  a  number  of  heavy  cords,  knotted  at  the  end,  hang  low  enough  to 
strike  the  face  and  shoulders  of  anyone  who  passes  below  it.  He  is  thus  made 
aware  of  the  fact  that  he  is  approaching  a  winze  or  chute  and  must  be  careful 
about  passing  that  place. 

Gate  for  Ore -bin  Chutes  (By  Algernon  Del  Mar).— The  accompanying 
illustrations  show  what  in  my  opinion  is  one  of  the  best  gates  for  ore-bin  chutes. 


fel 

A 

n 
T] 

G/  A 

of  Chute 


FIG.   88. — GATE  FOR  ORE  BIN  CHUTES. 

It  does  not  choke  readily  and  can  be  used  for  coarse  or  wet  as  well  as  fine  or  dry 
ore.  A  gate  of  this  type  was  furnished  by  the  A.  Leschen  &  Sons  Rope  Co. 
for  the  automatic  loading  station  of  their  aerial  tramway  that  I  erected  in  Modoc 
county,  Calif.  The  sliding  gate  acts  from  below  by  a  lever  and  slides  up  and 
down  on  wheels  in  a  recess  on  the  side  of  the  ore  chamber,  but  in  such  a  way 
that  the  ore  cannot  get  into  these  recesses.  A  boy  can  operate  it  and  can  load 
cars  as  fast  as  they  can  be  run  under  the  lip  of  the  chute.  When  loading  must  be 
done  expeditiously,  for  example  where  a  train  of  cars  must  be  loaded,  I  believe 
they  could  be  loaded  by  the  use  of  this  gate  while  in  motion.  The  amount  of 
ore  going  through  the  chute  is  that  sliding  over  the  top  when  the  gate  is  let  down 
and  nothing  can  choke  the  return  of  the  gate  to  the  position  where  it  cuts  off  the 
stream  of  ore.  Referring  to  Fig.  88,  A  is  a  steel  chute,  B  a  sliding  gate  actuated 


144  HANDBOOK  OF  MINING  DETAILS 

by  the  levers  C,  D,  and  E.  By  lifting  the  lever  E  the  gate  is  lowered  allowing  the 
ore  to  run  over  the  top  of  the  gate.  As  the  top  of  the  gate  can  be  lowered  until 
it  is  flush  with  the  bottom  of  the  chute  there  is  a  clear  passage.  When  it  is 
desired  to  shut  off  the  stream  of  ore  the  lever  E  is  depressed  throwing  the  gate 
up.  A  A  is  the  ore  chute,  G  is  the  slot  in  the  bottom  thereof  through  which  the 
gate  moves  in  a  vertical  direction,  B,  B  are  the  recesses  or  chambers  in  which  the 
wheels  which  are  attached  to  the  sides  of  the  gate  slide  up  and  down,  so  that  the 
movement  of  the  gate  takes  little  effort. 

Ore  Crushing  Plant  Underground. — A  crushing  and  screening  plant  is 
being  installed  underground  in  the  Round  Mountain  mine,  at  Round  Mountain, 
Nev.  It  will  be  placed  on  the  45o-ft.  level,  and  will  be  similar  to  a  plant  already 
installed  in- the  "Stringer  Section."  As  mined,  the  ore  contains  many  large 
boulders  of  rock,  which  itself  is  barren,  but  may  envelop  pieces  of  ore.  In  order 
to  save  this  ore  it  i?  necessary  to  crush  the  boulders  and  sort  the  crushed  material. 
The  plant  will  comprise  a  12 X  2o-in.  jaw  crusher,  and  an  i8-in.  belt  conveyor  to 
carry  the  crushed  material  to  a  trommel  10  ft.  long  by  40  in.  diameter,  which 
will  be  set  above  loading  pockets  cut  out  of  the  rock  above  the  level.  The 
fine  material  will  be  trammed  to  the  shaft,  hoisted  and  sent  to  the  mill.  The 
waste,  or  coarse  material,  will  be  hauled  by  mules,  through  a  tunnel,  to  daylight. 
According  to  the  last  annual  report  of  the  Round  Mountain  Mining  Co.,  the 
crusher  installation  will  effect  great  economies  in  handling  and  sorting  the 
material  mined.  A  better  grade  of  ore  will  be  produced,  as  under  these  new 
conditions  about  66%.  of  the  gross  tonnage  mined  will  be  rejected  as  waste 
whereas  during  the  last  year  54%  was  rejected.  It  will  also  increase  the 
total  recovery  of  precious  metals  as  it  will  be  possible  to  send  to  the  mill  the 
greater  part  of  the  ore  contained  in  the  boulders,  which  heretofore  has  been 
rejected  with  the  waste. 

Underground  Grizzlies. — Much  trouble  has  been  experienced  in  the  mines 
in  the  Ducktown  district  of  Tennessee  from  the  ore  in  the  stopes  breaking  into 
such  large  pieces  that  it  could  not  be  handled  or  would  not  run  in  chutes  without 
blocking.  In  the  large  underhand  stopes,  when  the  ore  is  milled  down  to  the 
haulage  level  in  benches  from  5  to  7  ft.  high,  this  difficulty,  although  annoying, 
is  not  serious,  as  the  miners  with  blocking  drills  can  easily  drill  the  large  lumps 
and  shoot  them  into  such  pieces  as  can  be  handily  loaded  into  the  tram  cars. 
However,  in  using  a  system  of  mining  in  which  the  ore  is  drawn  from  the  stopes 
in  chutes  this  difficulty  at  times  becomes  so  serious  as  to  preclude  the  possibility 
of  drawing  the  ore  from  the  stopes  through  chutes.  At  the  Tennessee  Copper 
Co.'s  mines  several  types  of  chute  gate  have  been  tried  in  connection  with  their 
shrinkage  or  back  stopes,  but  none  has  given  any  satisfaction,  all  being  liable 
to  choking  from  the  large  masses  of  ore  which  they  have  to  deliver. 

Recently,  however,  J.  V.  Bohn,  superintendent  of  mines  for  the  Tennessee 
Copper  Co.,  has  introduced  a  type  of  underground  grizzly  in  the  Burra  Burra 
mine,  which  has  proven  so  successful  that  in  the  future  it  will  be  used  in  con- 


STOPING  145 

nection  with  all  the  shrinkage  stopes  where  large  pieces  of  ore  have  to  be  dealt 
with,  i.e.,  on  the  hanging- wall  side  of  the  orebodies  where  the  larger  lumps  tend 
to  gravitate.  These  grizzlies,  as  shown  in  Fig.  89,  are  very  simple  and  require 
practically  no  repairs  for  maintenance.  An  opening  is  made  into  the  side  of 
the  haulage  way  or  drift  and  a  platform  cribbed  up  with  ioX  10  timbers  on 
either  side,  leaving  a  space  into  which  a  car  may  be  run  from  the  drift.  Across 
the  top  of  the  opening  left  for  the  car,  old  track  iron  is  laid  at  1 5-in.  spacing, 


FIG.    89. — ARRANGEMENT  AND   CONSTRUCTION   OF   UNDERGROUND   GRIZZLY. 

the  iron  being  seated  in  the  timbers  on  either  side.  At  either  side  of  the  plat- 
form openings  are  made  to  the  stope  above,  these  being  made  large  enough  so 
that  ore  of  any  size  liable  to  be  encountered  will  be  readily  delivered  upon  the 
platform. 

To  fill  the  car  the  trammer  simply  runs  it  under  the  grizzly  and  with  a  pick, 
draws  ore  from  the  mouth  of  the  chute  over  to  the  grizzly  bars,  the  fines,  or 
materials  of  such  size  as  can  be  handled  by  the  crusher,  passing  through  the  bars, 
while  large  lumps  are  retained  on  the  platform.  These  can  be  readily  blocked 
while  still  on  the  platform,  with  no  danger  of  destroying  the  grizzly,  there  being 
no  gates  or  movable  parts  to  the  device. 


146 


HANDBOOK  OF  MINING  DETAILS 


A  Movable  Picking  Floor. — A  picking  floor  used  by  Witherbee,  Sherman 
&  Co.  for  ore  that  will  not  pass  through  a  6-in.  grizzly  consists  of  a  movable  chute 
5  ft.  wide  and  1 2  ft.  long,  built  of  heavy  sheet  iron,  with  sides  i  ft.  high.  One 
end  is  supported  or  hinged  just  below  the  chute  from  the  ore  bin.  The  platform 
is  practically  level,  and  a  ton  or  more  of  lump  ore  is  discharged  upon  it  at  a  time, 
and  two  men  pick  out  the  barren  rock.  When  the  platform  is  full  of  ore,  the 
outer  end  is  lowered  by  an  air-hoist  and  the  ore  slides  directly  into  the  car  for 
shipment.  The  second-class  ore  is  tossed  to  a  car  on  an  adjoining  track,  while 
the  waste  rock  is  disposed  of  by  means  of  a  bucket  suspended  from  a  carrier 
which  operates  on  an  I-beam. 

A  Modified  "Chinaman."— A  modification  of  the  chute  known  as  the 
"chinaman,"  has  recently  been  put  into  use  in  the  shrinkage  stopes  of  the  Cop- 


FIG.    90. — THE    IMPROVED    " CHINAMAN." 

per  King  mine,  at  Clifton  Ariz.,  by  L.  W.  Armstrong,  superintendent.  It  was 
found  that  the  " loose,  sliding"  boards  covering  the  opening  in  the  center  of  the 
platform  would  not  slide  easily,  or  at  all,  when  covered  with  ore  from  the  stope, 
making  it  extremely  onerous  to  open  the  chute  and  to  close  it  when  the  car  was 
filled.  The  difficulty  was  overcome  by  nailing  a  cleat  of  2 -in.  stuff  to  the  inside 
of  each  of  the  stulls  supporting  the  platform  and  fitting  in  2X6's  from  stull  to 
stull  on  either  side  of  the  opening  above;  these  2X6's  support  loose  boards  B, 
as  shown  in  Fig.  90,  which  can  be  easily  moved  by  hand  or  with  a  short,  sharp- 
pointed  bar.  Two  of  the  loose  boards  A  on  the  platform  are  removed,  leaving 
a  permanent  opening.  It  was  found  expedient  to  raise  the  platform  about  3  ft. 
above  the  top  of  the  car  as  it  enabled  the  trammer  to  get  at  the  chute  door  more 


STOPING 


147 


easily,  and  also  avoided  the  inconvenient  reduction  in  the  height  of  the  level  at 
the  "chinaman." 

Ore  Chute  Construction. — Ore  chutes  of  standard  design  are  used  in  the 
mines  of  the  Goldfield  Consolidated  company,  at  Goldfield,  Nev.,  to  deliver 
ore  from  stopes  to  main  haulage  tunnels.  Light,  steel,  arc  gates,  with  a  long 
lever  handle,  are  provided  for  the  chutes.  Fig.  91  gives  the  dimensions  and 
details  of  the  standard  chutes.  Posts  of  the  drift  or  tunnel  sets  are  placed  at 
5-ft.  centers,  allowing  an  opening  4  ft.  2  in.  wide  (ioX  lo-in.  timbers  are  used) 
or  8-in.  clearance  on  either  side  of  the  ore  cars.  The  drifts  are  8  ft.  high  in  the 
clear.  The  bottom  of  the  chute  is  inclined  at  an  angle  of  about  35°  from  the 
horizontal  and  passes  through  the  next  set  to  one  side  of  the  drift.  It  is  sup- 


Side  Front 

FIG.    91. — STANDARD    ORE   CHUTE   IN   GOLDFIELD   CONSOLIDATED   MINE. 

ported  by  a  piece  of  8X  8  in.  timber  set  with  its  upper  face  parallel  to  the  inclina- 
tion of  the  chute  bottom  and  let  at  its  ends  into  the  posts  at  either  side  of  the 
chute.  The  lip  of  the  chute  extends  5  1/2  in.  over  the  edge  of  the  tram-car.  A 
double  lining  of  2-in.  plank  is  used  on  the  bottom  of  the  chute.  The  sides  are 
made  of  one  thickness  of  plank.  The  chute  is  carried  the  full  width  of  the  set 
from  the  stope  to  the  lip,  which  is  tapered  down  to  a  width  of  2  ft.  10  in.  The 
body  of  the  cars  used  is  3  ft.  5  in.  long.  So  as  to  allow  the  gates  to  be  readily 
closed  against  the  stream  of  ore,  the  gate  should  be  set  at  such  an  angle  that  as 
soon  as  the  stream  of  ore  is  intercepted  its  force  tends  to  close  the  gate. 

A  Standard  Ore  Chute  (By  S.  S.  Arentz).— The  type  of  ore  chute  shown 
in  Fig.  92  is  the  standard  in  use  at  the  mines  of  the  Nevada-Douglas  Copper  Co. 
As  a  rule  it  has  proved  to  be  satisfactory  in  most  places  in  which  it  has  been 
used  where  no  special  conditions  require  a  chute  of  different  construction.  At 
the  Nevada-Douglas  mines  the  chute  is  always  built  of  the  same  size  of  timbers, 
the  different  pieces  being  framed  at  the  surface  and  sent  underground  ready  to 


148 


HANDBOOK  OF  MINING  DETAILS 


be  put  together.  In  the  illustration  the  3-in.  chute  bottom  is  shown  supported 
by  a  round  timber  at  the  top  of  the  set,  but  it  is  often  supported  directly  by  the 
ground  as  the  post  supporting  the  main  drift  set  is  not  used.  While  no  originality 
is  claimed  for  this  design,  such  chutes  are  often  built  without  adherence  to  any 


wedged  into  Hitch 
where  possible  with- 
out use  of  Post. 


Sills  not  shown.  Front  View. 

Side  View. 

FIG.    92. — STANDARD    ORE   CHUTE   USED  AT  NEVADA-DOUGLAS   MINES. 

standard  of  dimensions  and  those  in  various  parts  of  the  same  mine  vary  in  size 
and  construction.  There  are  many  advantages  in  building  chutes  to  standard 
dimensions  other  than  those  gained  by  being  able  to  do  all  the  framing  at  the 
surface. 


VII 


HEADFRAMES,  CHUTES,  POCKETS,  ETC. 

Gates  for  Chutes  and  Bins— Headframes,  Tipples  and  Derricks— Ore  Bins. 

Gate  for  Ore  Chute. — In  both  the  Angels  Quartz  and  Utica  mines  at  Angels 
Camp,  Calif.,  gates  of  very  simple  construction  are  used  on  ore  chutes.  The 
gate  itself  is  a  rectangular  piece  of  sheet  iron  or  steel,  usually  1/4  or  3/8  in.  thick, 
sliding  between  strips  of  iron  nailed  to  the  sides  of  the  chute.  A  piece  of  round 
drill  steel  is  fixed  to  the  gate,  being  riveted  and  countersunk  on  the  inside  and 
having  an  iron  ring  shrunk  about  it  on  the  outside  of  the  gate,  thus  serving  to 
hold  it  firmly.  A  long  curved  iron  bar  is  pivoted  on  the  side  of  the  chute  so  that 
the  short  end  engages  the  lug  on  the  gate.  Thus  by  moving  the  bar  the  gate  is 
opened  or  shut.  In  the  Utica  a  piece  of  drill  steel  is  used  for  the  bar,  which  may 
be  slipped  off  at  will. 

Chute  Gate  at  Mammoth  Mine,  Kennett,  Calif. — At  the  mine  of  the 
Mammoth  Copper  Mining  Co.,  near  Kennett,  Shasta  county,  Calif.,  an  excellent 


o                                                                                                                                      a 

/  .. 

'       1 

"2                     Gate           H*  Plate 

,              fo\  

Eh 
> 

Augle  Iron' 

_/o~| 

^L_ 

&  -For  Lever 

_T~ 

-For  Lever 

2'//x  l" 
For  Lever/   c 

Plate 


Augle  Irons 


-For  Lever 


FIG.    93. CHUTE    GATE  AT   MAMMOTH   COPPER   MINE. 

type  of  iron  gate  for  an  ore  chute  is  in  use  on  the  large  ore  passes  from  the  stopes 
where  top-slice  caving  is  being  done.  A  large  amount  of  ore  must  be  handled 
quickly  through  these  chutes,  so  that  it  requires  a  strong  gate  with  a  positive 
action.  The  details  of  the  gate  are  shown  in  Fig.  93.  The  particular  feature  of 
the  Mammoth  chute  gate  is  that  it  is  closed  by  raising  a  door  through  the  stream 

149 


HANDBOOK  OF  MINING  DETAILS 


of  ore  passing  from  the  chute  instead  of  by  lowering  one,  as  in  the  ordinary  types. 
Where  ore  is  running  rapidly  through  a  chute,  it  is  quite  difficult  to  lower  a  gate 
into  this  quickly,  whereas  lifting  the  gate  through  the  stream  of  ore  presents  no 
difficulty.  The  frame  of  the  chute  gate  is  made  of  two  angle  irons,  bent  as 
shown,  between  which  the  gate  of  3/8-in.  steel  slides.  One  angle  iron  is  cut 
away  on  the  lower  part  of  the  frame.  A  bar  of  2  i  /  2  X  i-in.  iron  is  bolted  to  the 
lower  side  of  the  gate  and  slides  through  a  guide  at  the  lower  part  of  the  frame. 
The  gate  is  operated  by  a  lever  connected  to  this  bar  and  pivoted  on  the  frame. 
Sheets  of  3/8-in.  steel  cut  as  shown  in  the  drawing,  are  riveted  to  the  frame  and 
form  an  extension  of  the  sides  of  the  chute  and  a  projecting  lip.  The  entire 
gates  are  riveted  together  and  set  up  before  being  taken  into  the  mine,  so  that 
they  are  ready  to  be  set  in  place  in  the  ore  chutes.  The  all-steel  construction  of 
this  chute  gate  renders  it  substantial,  but  at  the  same  time  rather  expensive,  so 
that  its  use  is  only  warranted  where  large  quantities  of  ore  are  handled. 

Gate  for  Lump  Ore  Bin  (By  Guy  C.  Stoltz). — A  gate  commonly  used  on 
lump-ore  bins  at  the  iron  mines,  Mineville,  N.  Y.,  is  shown  in  Fig.  94.     The 


_  \VPInte: 

Section 

FIG.    94. — AIR-HOIST   GATE  FOR  COARSE 


3  Plank,  supported 
by  G"X  8"Sticks 


Side  Elevation 

One  Column 

removed. 


ORE. 


gate  is  made  of  2  i/2-in.  plank,  with  an  outside  steel  plate,  1/4  in.  thick,  4  1/2  ft. 
square,  and  an  inside  plate  of  same  area  and  i  /  2  in.  thick.  Three  axles,  21/2 
in.  square,  turned  to  2  1/4  in.  diameter  at  the  ends  to  receive  rollers  of  4  in. 
diameter  and  2  in.  face,  are  bolted  between  the  plates.  The  2  i/2-in.  plank 
acts  as  a  cushion,  also  gives  weight  and  stiffness  to  the  gate.  The  rollers  run  in 
the  guides  formed  by  riveting  4X4-in.  angles  to  the  two  i2-in.  I-beam  columns. 


HEADFRAMES,  CHUTES,  POCKETS,  ETC.  151 

On  the  bottom  of  the  gate  a  heavy  3-in.  angle  iron  is  riveted  to  the  plates  to 
protect  them  from  wear.  The  addition  of  two  rollers  to  each  side  working  at 
right  angles  to  main  rollers  would  improve  the  gate  by  lessening  the  friction  due 
topside  motion,  for  then  any  binding  of  the  gate  would  be  met  by  roll  faces.  The 
gate  is  fitted  to  a  timber  headframe  by  having,  say,  ioX  lo-in.  posts  take  the 


FIG.    95. — FINGER  CHUTE   FOR   FILLING   WHEELBARROWS. 

place  of  I-beams  and  4X4-in.  hardwood  strips  bolted  to  posts  to  act  as  guides. 
This  latter  type  is  generally  used  at  the  underground  storage  pockets  where  it 
is  essential  to  have  a  positive  working  gate  which  will  close  the  instant  the  skip 
has  been  filled.  S.  L.  LeFevre,  assistant  general  manager  for  Witherbee,  Sher- 
man &  Co.,  designed  the  gate. 


152 


HANDBOOK  OF  MINING  DETAILS 


A  Finger  Chute  (By  A.  Livingstone  Oke).— An  adaptation  of  the  well-known 
finger  chute  employed  by  me,  while  manager  of  a  mine  in  Chihuahua,  Mexico, 
is  shown  in  Fig.  95.  The  ore  coming  into  the  breaker  floor  from  an  aerial 
tramway  was  being  dumped  direct  on  a  grizzly,  the  fines  going  into  the  battery 
bin  and  the  oversize  accumulating  on  the  floor  above,  whence  it  was  shoveled 
into  wheelbarrows  and  taken  to  the  breaker.  To  avoid  the  shoveling,  the 
finger  chute  was  put  in  and  two  out  of  three  peons  were  displaced.  The  fingers 
receive  hard  usage  and  should  be  built  strongly.  Their  weight  keeps  the  ore 
back,  as,  from  the  position  of  the  fulcrum,  they  may  be  considered  to  have  their 
center  of  gravity  just  where  it  is  most  effective,  i.e.,  in  front  of  the  sliding  ore. 
They  are  easily  controlled  and  saved  all  the  hard  work  of  shoveling.  Other 
types  of  chute  were  tried,  but  failed  to  be  of  service. 

Steel  Arc  Chute  Gate. — A  strong  and  durable  arc  chute  gate  of  simple 
pattern  is  used  on  the  flat-raise  ore  pocket  in  the  Pittsburg- Silver  Peak  mine, 


FIG.    96. — STEEL  ARC   CHUTE   GATE  AT   PITTSBURG-SILVER   PEAK  MINE. 


near  Blair,  Esmeralda  county,  Nev.  The  entire  output  of  the  mine,  about  500 
tons  per  day,  is  handled  through  these  chutes;  hence  gates  sufficiently  strong  to 
withstand  the  wear,  and  with  a  positive  action,  must  be  used.  The  type  shown 
in  Fig.  96  has  given  satisfaction.  The  frame  of  the  gate  is  made  of  two  pieces  of 
3/4X3-111.  iron  bent  on  an  arc  with  a  radius  of  22  1/2  in.  and  turned  back  at 
either  end,  and  bolted  with  i-in.  bolts,  to  the  hub  of  the  gate.  These  pieces  of 
3/4-in.  iron  are  spaced  i  in.  from  the  edge  of  the  gate  and  fastened  to  the  3/8-in. 
sheet  steel  that  forms  the  arc  of  the  gate,  with  four  3/4-01.  rivets.  By  using  single 
pieces  of  heavy  iron  to  fasten  the  arc  to  the  hub  and  extending  entirely  across 
either  end  of  the  gate  segment  added  stiffness  is  obtained.  The  hubs  are  3  in. 
thick,  6  in.  wide,  10  3/4  in.  long  and  bored  for  a  2  3/i6-in.  axle.  One  of  the 
chief  advantages  of  this  type  of  gate  is  in  the  few  parts  required  for  its  construc- 
tion, and  hence  the  simplicity  of  setting  it  up.  There  are  only  five  pieces  to  the 
gate  and  for  putting  them  together,  four  bolts  and  eight  rivets  are  required. 


HEADFRAMES,  CHUTES,  POCKETS,  ETC. 


153 


The  components  of  the  gate  are  a  piece  of  3/8-in.  sheet  steel,  34X  26  1/4  in.,  U 
form  the  arc  segment  of  the  gate,  two  3/4X3-^.  iron  bars,  33  1/4  in.  long,  for 
the  frames  or  spokes,  two  cast-iron  hubs  of  the  pattern  shown  in  the  drawing, 
eight  3/4-in.  rivets,  and  four  i-in.  bolts. 

Cananea  Arc  Type  Gate. — The  arc-type  gate  shown  in  Figs.  97  and  98  is 
used  in  the  ore-bin  chutes  at  the  mines  at  Cananea,  Mexico.     It  may  also  be 


FIG.    97. — ELEVATION   OF  CANANEA   BINS. 


modified  for  use  in  underground  chutes.  The  novel  feature  of  the  gate  is  the 
axle  which  is  made  of  round  iron  bent  as  shown  in  the  lower  part  of  Fig.  98. 
The  center  of  the  rod,  of  which  the  axle  is  made,  is  flattened  and  bolted  to  the 
sheet  forming  the  door.  The  position  of  the  gate  in  the  ore  bin  is  shown  in 
Fig.  97,  in  which  illustration  is  also  shown  the  manner  of  building  the  steel 
chute,  below  the  gate,  so  that  there  is  a  hinged  lower  portion  which  is  counter- 


'54 


HANDBOOK  OF  MINING  DETAILS 


balanced  by  a  weight  permitting  the  swinging  of  that  portion  of  the  chute  up 
and  out  of  the  way  of  passing  trains.  The  details  of  the  steel  chute  are  shown 
in  the  upper  part  of  Fig.  98.  A  runway  is  built  in  front  of  the  bins  to  give  easy 
access  to  the  handles  operating  the  gates  and  so  that  the  operator  can  take  a  posi- 
tion above  the  top  of  the  car  he  is  loading 


End.  Front. 

FIG.    08. — DETAILS    OF   METAL   PART   OF  ARC-TYPE   GATE   FOR   CHUTES. 


SKIP  LOADERS 

Skip  Loader  at  the  Original  Consolidated. — At  the  Original  Consolidated 
mine,  Butte,  Mont.,  a  novel  skip-loading  arrangement  is  being  used  in  place  of 
the  ordinary  ore  pocket  discharging  directly  into  the  shaft.  The  ground  at  this 
mine  is  rather  heavy  and  it  was  not  thought  advisable  to  take  away  support  from 
the  shaft  by  cutting  out  the  ground  for  skip-pockets.  By  using  small  apron 
chutes  mounted  on  wheels,  the  skips  were  formerly  loaded  directly  from  cars. 
This  method  is,  however,  slow  and  requires  too  much  labor  shifting  and  dump- 
ing the  cars,  etc.  To  avoid  this,  the  arrangement  shown  in  Fig.  99  was  devised 
and  has  already  been  installed  on  several  levels  of  the  mine.  Above  the  ordinary 
station,  10  ft.  high  in  the  clear,  an  additional  space,  61/2  ft.  clear  above  the 
station  proper,  is  cut  and  timbered  with  I2X  i2-in.  material.  The  top  of  the 
station  timbers  forms  a  platform  upon  which  a  man  can  stand  while  operat- 
ing the  air  gates  on  the  chute.  At  the  third  station  set  from  the  shaft  a  two- 
compartment  raise,  inclined  toward  the  station  at  80°  from  the  horizontal,  is  put 
up  to  the  level  above.  This  chute  is  carried  4  ft.  10  in.  square  overall  and  is 
timbered  with  loX  lo-in.  material  framed  in  y-ft.  sets,  with  dividers  of  5X10 


HEADFRAMES,  CHUTES,  POCKETS,  ETC. 


155 


FIG.  99. — SKIP  LOADING  ARRANGEMENT  FOR  ORIGINAL  CONSOLIDATED  MINING  CO.,  BUTTE,  MONT. 


156 


HANDBOOK  OF  MINING  DETAILS 


material  midway  of  each  set.  The  chute  compartments  are  lined  with  5X10 
material  on  the  bottom,  and  3X10  on  the  top  and  sides.  The  inclined  raise 
terminates  at  its  lower  end  in  the  hopper-bottom  pocket  A.  The  chutes  are 
provided  with  steel  gates,  operated  by  compressed-air  cylinders  B.  The  dis- 


Measure 

Holding  One  Skip 
of  Ore 


FIG.    IOO. — SKIP-LOADING  ARRANGEMENT  AT   SCRANTON   MINE,   HIBBING,    MINN. 

charge  is  into  a  long  sheet-steel,  swinging  spout  C,  the  lip  D  of  which,  when 
turned  down  projects  into  the  shaft  far  enough  to  deliver  rock  into  the  skip. 
The  steel  apron-chute  is  pivoted  at  its  top  end,  so  that  the  lower  or  discharge 
end  may  be  swung  to  either  shaft  compartment.  This  chute  is  supported  by  a 
chain  E,  that  is  fastened  to  the  pulley  F.  This  pulley  runs  on  a  short  track,  thus 


HEADFRAMES,  CHUTES,  POCKETS,  ETC. 


157 


enabling  the  spout  to  be  easily  swung.  The  lip  of  the  spout  is  connected  by  a 
line,  passing  over  two  blocks,  to  the  counterbalance  G.  This  weight  serves  to 
keep  the  lip  raised,  so  that  the  spout  will  swing  clear  of  the  shaft  timbers.  The 
counterbalance  is  lifted  and  the  lip  let  down  when  a  skip  is  to  be  loaded,  the 
spout  being  swung  out  of  the  way  when  not  in  use. 

When  loading  a  skip,  one  man  climbs  up  to  the  platform  and  operates  the  air 
gate  on  the  raise  (or  pocket),  while  another  swings  the  spout,  lowers  the  lip 
and  calls  out  when  the  skip  is  filled.  By  having  the  loading  arrangement  at  a 
station  instead  of  below  in  the  shaft,  time  and  labor  are  saved.  The  inclination 
of  the  raise  carries  it  to  the  level  above  at  a  point  far  enough  away  from  the  shaft, 
so  that  the  nuisance  of  having  cars  block  the  station  is  done  away  with.  Having 
the  approach  to  the  shaft  clear  is  an  important  advantage  of  this  skip  loader. 


Ore  Pocket 


FIG.    101. — GATE   FOR   SKIP-LOADING   CHUTE,  GRANBY    CONSOLIDATED    MINES. 

Measuring  Pocket  for  Skips. — A  skip  pocket  designed  by  C.  F.  Jackson 
for  the  Scranton  mine  at  Hibbing,  Minn.,  is  shown  in  Fig.  100.  The  principal 
feature  that  commends  this  pocket  is  the  fact  that  it  opens  in  such  a  way  that 
the  shaft  is  clear  at  all  times.  A  number  of  similar  pockets  are  in  use,  but  they 
open  into  the  shaft  and  are  more  or  less  dangerous.  In  addition  this  pocket 
provides  a  safe  place  for  the  operator.  He  is  on  the  platform  above  the  pocket. 


158 


HANDBOOK  OF  MINING  DETAILS 


One  man  can  both  draw  the  ore  from  the  chute  and  fill  the  skip  from  this  pocket 
which  holds  just  one  skip  load,  91  cu.  ft.  The  pocket  is  opened  by  means  of  a 
rope  and  pulley.  As  the  rope  is  moved  it  turns  the  lower  pulley  off  center  and 


„                 i 

Loading 

--12— 

Skip 

—  %  Rivets 

f'T 

FIG.    102. — THE   WHITFORD    MILLS   SKIP-LOADING   DEVICE. 

the  weight  of  the  ore  opens  the  pocket.     The  chain  prevents  the  wheels  from 
turning  too  far  past  the  center. 

Skip  Loading  Chute. — Details  of  an  ore  chute  for  loading  skips  used  at  the 


HEADFRAMES,  CHUTES,  POCKETS,  ETC.  159 

mines  of  the  Granby  Consolidated  company,  Phoenix,  B.  C.,  are  shown  in 
Fig.  1 01.  It  is  an  improved  form  of  finger  chute,  combining  fingers  with  a 
sheet-iron  gate  for  holding  the  fines.  In  the  operation  the  sheet-iron  gate 
is  raised  first  by  the  air  lift,  then,  as  the  arm  is  raised  still  higher  by  the  piston  of 
the  air  cylinder,  the  fingers  are  raised  and  the  coarse  ore  allowed  to  escape.  When 
the  air  is  released  the  fingers  fall  first,  catching  the  coarse  rock,  and  there  is  a 
sufficient  interval  of  time  for  the  chute  to  clear  itself  before  the  sheet-iron  gate  is 
closed.  The  operation  is  rapid  and  the  skips  are  filled  nearly  as  fast  as  the  skip 
tender  can  operate  the  valves. 

Whitford-Mills  Skip  Loading  Device  (By  E.  M.  Weston).— An  appara- 
tus for  loading  hoisting  skips  devised  by  Messrs.  Whitford  and  Mills,  respec- 
tively general  manager  and  engineer  of  the  City  Deep,  Ltd.,  Johannesburg,  S.  A., 
is  shown  in  Fig.  102.  It  is  designed  to  load  5-ton  skips  faster  than  could  be  done 
by  means  of  Kimberley  chutes.  The  idea  consists  essentially  of  a  second  skip  in 
each  compartment  in  front  of  the  main  doors  of  the  bin  at  the  bottom  of  the 
shaft.  These  skips  hold  five  tons,  as  do  the  skips  in  the  shaft,  and  are  to  be  filled 
from  the  bin  while  the  hoisting  skips  are  running  in  the  shafts.  They  are  hung 
at  A  and  balanced  so  that  their  movement  while  tipping  is  controlled  by  guides 
B,  in  such  a  manner  that  the  hoisting  skips  on  their  descent  tips  them  automatic- 
ally by  engaging  the  hooks  C  on  either  side.  The  loading  skips  themselves  never 
project  into  the  shaft  even  while  tipping.  In  this  manner  hoisting  could  be 
carried  on  without  any  pause  except  for  reversing  the  engines,  say  15  seconds. 
One  possible  drawback  to  the  use  of  the  device  might  be  the  possibility  of 
damage  to  the  apparatus  by  a  skip  reaching  the  loading  station  with  too  much 
velocity;  but  as  electric  winding  is  rapidly  being  adopted,  this  system  can  easily 
be  adjusted  for  automatic  action,  and  steam  winding  engines  could  also  be 
provided  with  one  of  the  well-known  types  of  automatic  reversing  and  breaking 
devices. 

Red  Jacket  Ore  Pockets.— The  Red  Jacket  shaft  of  Calumet  &  Hecla  is 
the  one  shaft  in  the  United  States  equipped  with  a  Whiting  hoist.  This  is  used 
in  raising  the  ore,  while  an  ordinary  drum  hoist  is  used  for  raising  men.  Skips 
holding  71/2  tons  are  used  and  the  shaft  is  arranged  so  that  the  pockets  for  the 
different  skips  are  on  alternate  levels.  These  skip  pockets  are  large  enough  to 
hold  9  tons,  but  only  three  cars,  a  skip  load,  are  dumped  in  at  a  time.  The 
pocket  is  lined  with  steel,  on  top  of  which,  both  on  the  sides  and  bottom,  wear- 
ing plates  are  bolted.  The  steel  bottom  plate  rests  on  a  cast-iron  bottom  plate 
4  in.  thick  which  in  turn  rests  on  a  bottom  of  12  X  i2-in.  timbers,  as  trouble  was 
experienced  with  the  steel  bottom  plate  when  it  rested  directly  on  the  timber 
bottom  on  account  of  the  size  of  the  boulders — some  weighing  a  ton  and  a  half — 
that  are  dumped  from  the  cars  into  the  skip  pocket. 

This  skip  pocket  has  a  hand-operated  swinging  door  as  shown  in  Fig.  103. 
The  door  piece  A  is  hinged  at  the  top,  the  strain  on  the  hinge  seats  being  carried 
back  to  rock  wall  of  the  pocket  pit  by  means  of  two  bolts  equipped  with  turn- 


i6o 


HANDBOOK  OF  MINING  DETAILS 


buckles.  A  lever,  B,  leads  back  from  this  door  to  the  main  locking  lever,  C,  to 
which  it  is  connected  by  a  pin  joint.  The  door  as  it  swings  back  after  it  is 
released  by  easing  on  the  band  brake  (with  which  the  shaft  of  the  locking  lever  is 
equipped  so  as  to  prevent  the  return  of  the  door  before  the  pocket  has  emptied 
itself,  as  might  be  the  case  if  there  was  much  fine  ore  in  the  pocket)  forces  this 
locking  lever  past  dead  center  so  that  the  weight  of  the  ore  pressing  against  the 
door  holds  the  lever  against  the  inside  stop  that  limits  its  downward  motion. 
The  outward  swing  of  the  door  is  limited  by  the  locking  lever  coming  in  contact 
with  a  similar  stop  at  the  other  end  of  its  range  of  travel.  In  case  that  this  lock- 


Elevation  Looking  West 
FIG.    103. — DETAILS    OF  A   STEEL   ORE    POCKET   IN    RED   JACKET   SHAFT. 

ing  lever  sticks  so  that  a  man  cannot  conveniently  start  it  by  a  moderate  lift 
on  its  outer  end,  the  skip  tender  resorts  to  the  use  of  a  wooden  auxiliary  lever 
that  is  fastened  to  the  back  post  of  the  pocket  so  as  to  aid  in  starting  the  locking 
lever;  but  this  is  not  usually  necessary.  To  bridge  the  gap  between  the  skip  and 
the  mouth  of  the  pocket,  an  apron  E,  is  provided,  which  is  thrown  in  by  means 
of  either  of  two  levers  D,  shown  in  the  drawing.  This  apron  also  is  equipped 
with  a  wearing  plate. 

Measuring  Pocket  for  an  Inclined  Shaft. — The  North  Kearsarge  shaft 
No.  4  is  sunk  in  the  foot  wall  of  the  lode,  and  the  ore  is  trammed  to  loading  bins 
at  the  shaft  that  serve  two  levels.  These  bins  are  covered  with  a  grating  of 
crossed  rails  so  that  boulders  must  be  broken  to  18  in.  to  go  into  the  bins.  On 
the  skip  chutes  proper  a  counterbalanced  arc  gate  that  closes  from  below 
through  a  system  of  togglelevers  is  used,  as  shown  in  Fig.  104.  On  the  measur- 


HEADFRAMES,  CHUTES,  POCKETS,  ETC. 


161 


ing  pocket,  doors  of  unique  design  are  used.  The  lower  one  opens  and  closes 
the  upper  gate  so  they  might  be  described  as  being  of  the  clam-shell  type. 
Owing  to  the  shape  of  the  levers  by  which  the  two  gates  are  suspended  the 
bottom  gate  moves  up  less  rapidly  than  the  top  gate  and  therefore  always 
closes  after  and  over  the  other.  This  is  illustrated  in  Fig.  104  which  shows  the 
gates  open  in  full  lines  and  closed  in  dotted  lines.  On  each  side  on  the  lower 
gate  is  a  semicircular  arm  in  the  top  of  which  is  a  notch.  Two  hooks,  connected 
by  a  bar  and  seated  on  the  posts  that  brace  the  bottom  of  the  measuring  pocket, 


Concrete 
Pier 


Concrete 
Stringer 


FIG.    104. — SKIP-LOADING   DEVICE  AT   OSCEOLA   MINE. 

drop  into  these  notches  and  latch  the  gates  in  position  when  they  are  closed.  By 
means  of  a  lever  these  hooks  are  raised,  then  the  weight  of  the  ore  forces  the 
back  door  backward  and  the  front  door  forward,  giving  the  ore  a  free  passage 
down  to  the  skip.  Extending  from  the  front  gate  are  the  arms  carrying  the 
counterweights,  one  on  each  side.  These  are  adjusted  so  that  a  slight  lift  is 
necessary  on  the  lever  arm  of  the  gates  to  close  them,  but  the  adjustment  is  so 
close  that  the  jar  of  the  skip  gate  as  the  skip  leaves  the  bin  will  close  the  doors. 
An  Underground  Ore  Pocket. — At  the  iron-ore  mines  of  the  Tennessee 


162 


HANDBOOK  OF  MINING  DETAILS 


Coal,  Iron  &  R.  R.  Co.,  on  Red  Mountain,  Ala.,  hoisting  is  done  in  skips  of 
lo-ton  capacity.  In  sinking  slopes  .without  an  ore  pocket,  the  skip  is  lowered 
until  it  rests  against  a  pentice  of  rock,  and  there  receives  ore  noisted,  by  an 
auxiliary  engine  from  the  face  of  the  slope,  in  2-ton  end-discharge  cars  .dumped 
by  an  ordinary  curved-rail  tipple.  These  2 -ton  cars  run  over  the  rock  pentice 
and,  when  no  pocket  is  used,  dump  directly  into  the  skip.  This  necessitates 
the  use  of  an  auxiliary  steel  car  which  can  be  attached  to  the  rear  of  the  skip  and 
pulled  out  with  it,  or  else  the  holding  of  the  skip  at  this  point  until  it  can  be 
filled  from  the  small  cars.  To  eliminate  this  waste  of  time,  an  underground 
pocket  is  used  in  the  slopes  of  the  Tennessee  company,  on  the  Ishkooda  and 


Section  of  Hopper 


Am 


\  /  Top  of  Rail 

"lope  Track  ^ 


ounterweight. 
Box  loaded  with 
Rock. 


Top  of  Rail 
Slope  Track 


Bars 


FIG.    105. — UNDERGROUND    ORE    POCKET 

Fossil  divisions.  The  design  and  method  of  setting  up  this  pocket  are  shown 
in  Fig.  105.  It  is  of  zo-ton  capacity,  and  is  set  so  that  the  skip  can  be  run  under 
the  pocket  and  filled  directly  without  any  loss  of  time.  The  pocket  is  hopper 
shaped,  and  made  of  i/4-in.  plate;  it  is  fitted  with  hinged  bottoms  opening  out- 
ward, as  shown.  These  bottom  doors  are  braced  with  4o-lb.  rails  at  the  ends, 
abutting  at  the  center  line  of  the  bottom  of  the  pocket.  To  the  ends  of  these 
rails  are  fastened  ropes  which  pass  up  and  over  two  2o-in.  sheave  wheels  and 
down  on  one  side  of  the  pocket  framing  where  they  are  connected  to  a  yo-lb. 


HEADFRAMES,  CHUTES,  POCKETS,  ETC. 


163 


rail.  A  latch  operated  by  a  lever,  details  of  which  are  shown,  holds  this  rail, 
and  consequently  the  gates  in  a  closed  position.  By  releasing  the  latch,  the 
weight  of  the  ore  is  allowed  to  open  the  pocket  bottom,  but  sufficient  counter- 
balance is  attached  to  the  yo-lb.  rail  to  swing  the  gates  closed  after  the  pocket 
has  discharged.  The  pocket  is  supported  from  two  lateral  12X12  timbers 
which  are  carried  on  12X12  cross-timbers  hitched  into  the  walls  of  the  slope. 

HEADFRAMES,  TIPPLES  AND  DERRICKS 

How  to  Erect  Three-leg  Shears  (By  A.  Livingstone  Oke).— The  correct 
way  to  erect  three-leg  shears,  using  a  tackle  and  rope  from  a  hand  or  power 


Foot  Hitch 


Method  of  Erecting 
Three-Leg  Shears 


Plank  for  foot  to  slide  on 


Alternative  Method, 
Applicable  with  Light  Shears 


Crorspiece    ^v 

Lashed  to  the 

two  Legs 


FIG.    I06. — PLAN  AND    ELEVATION   OF   THREE-LEG   SHEAVES. 

winch,  is  shown  in  Fig.  106.  The  three  legs  are  laid  out  first  on  the  ground,  as 
shown  in  the  plan,  two  of  them  being  placed  with  the  butt  ends  at  the  distance 
A  which  is  to  be  the  spread  of  the  shears  when  erected.  On  these  two  legs  a 
cross  piece  is  secured,  either  by  lashing  or  by  pegging  down,  as  shown  in  Fig.  i. 
One  end  of  the  tackle  is  attached  to  the  cross  piece  and  the  other  end  to  the 
single  leg.  It  is  necessary  to  lift  the  center  off  the  ground  2  or  3  ft.,  before 


164 


HANDBOOK  OF  MINING  DETAILS 


applying  the  power.  The  hauling  line  from  the  tackle  should  come  from  the 
single  leg  as  this  is  the  one  that  slides.  Boring  the  holes  for  passing  the  pin 
should  be  done  by  laying  out  the  three  legs,  as  shown  in  the  plan,  with  the  spread 
A  equal  to  the  proposed  base  when  erected.  In  this  way  there  is  no  risk  of  the 
pin  being  bent,  as  the  angle  between  these  two  legs  remains  constant  and  cannot 
be  altered  without  bending  the  pin.  The  height  of  the  shears  may  be  altered  by 
moving  the  middle  leg  nearer  or  further  from  the  other  two. 

Headframe  for  a  Prospect  Shaft. — The  sinking  of  a  prospect  shaft  is  often 
done  under  unnecessarily  dangerous  conditions.  It  is  taken  for  granted  that 
such  work  must  be  hazardous  because,  until  ore  has  been  found,  the  safety  of 
the  miners  is  not  regarded  as  warranting  extra  expense.  For  this  resaon  much 
prospecting  work  is  done  with  meager  equipment  and  poorly  constructed  head 
gear.  Until  a  depth  of  40  or  50  ft.  is  reached  a  windlass  may  be  used,  but  for 


4  x  24-in. 
-Bolts 


12-in. 


\8*  10 

T    ! 

10-in.^ 

1 

1-in.  Tie  BodB 

1 

8x  10- 

H-in.  Drift  Pins  1 

7-ft~3--i.il* 

18-in.  long 

a 

Drift  Pins 
10    /$?v"-  i-ln.  Tie  Bodi 


Sill  Plan. 


10-in. 


Vertical  Member.          Back  Brace. 


Side  Elevation. 


FIG    107. — PROSPECT  HEADFRAME  AT   SAND   GRASS   SHAFT. 


deeper  work,  to  a  limit  of  200  ft.,  a  horse  whim  will  be  needed,  which  requires 
nothing  more  than  a  tripod  to  support  a  sheave  about  1 5  ft.  above  the  collar  of  the 
shaft.  When,  however,  the  shaft  is  to  be  sunk  to  greater  depth  than  200  ft.  it  will 
be  found  more  economical  to  use  some  form  of  power  hoist;  generally  a  geared 
hoist  is  used.  A  power  hoist  will  require  a  substantial  headframe.  That  the 
headframe  need  not  be  inordinately  expensive  is  demonstrated  by  the  cost  of  the 
structure  shown  in  Fig.  107.  This  headframe  is  well  suited  to  the  purposes  of 
an  important  prospecting  shaft;  it  was  designed  by  ].  M.  Fox,  assistant  super- 
intendent for  the  Tonopah  Mining  Co.,  and  was  built  at  the  Sand  Grass  shaft. 
It  is  a  substantial  structure,  and  insofar  as  the  headframe  has  to  do  with  the 
safety  of  shaft  sinking,  provides  abundant  security.  With  such  headframes  it 


HEADFRAMES,  CHUTES,  POCKETS,  ETC. 


165 


has  been  possible  to  raise  100  tons  of  ore  per  day  through  a  one-compartment 
shaft  from  a  depth  of  300  ft.  without  crowding. 

The  headframe  is  quite  strong  enough  for  prospecting  work  and  is  designed 
for  use  with  a  cage  in  counterbalance  when  mining  of  ore  is  started.  In  case 
more  room  is  desired  about  the  collar  of  the  shaft,  the  lower  diagonal  brace 
can  be  made  vertical.  In  the  construction  of  this  headframe,  3200  board  feet 
of  8Xio-in.  timber  were  required.  All  daps  were  cut  i  in.  deep  and  painted 
with  creosote  to  protect  them  from  decay.  The  headframe  after  it  was  erected 
was  painted  in  order  to  preserve  it  from  the  weather.  The  wages  of  carpenters 
at  Tonopah  vary  between  $5  and  $5.50  per  8-hour  shift,  yet  the  cost  of  this 
headframe  complete  and  in  place  was  but  $330.  The  most  important  items 
were  3200  board  feet  of  lumber  at  $37.50  per  thousand;  framing  timbers  and 
erecting  labor,  $120;  iron  work,  $65.  A  3/4-in.  hoisting  rope  is  used  and  until 
actual  mining  begins,  or  while  the  shaft  is  being  sunk,  a  bucket  of  about  18  cu.  ft. 
or  a  little  over  i  ton  capacity  is  used  for  raising  rock. 

Headframe  for  a  Winze  Hoist. — In  mining  operations  it  is  frequently  the 
case  that  a  shoot  of  ore  has  been  followed  down  in  some  part  of  the  mine  remote 


6'x  S'x 


s  Tapped 


1 

8^    Loading  Bin 
6  x  s'lnslde  Measurement 
Framework  6"x  C'Timbei 
Bottom  S'x  ItfVlank 
Sides  tsjrClMh 


FIG.    IO8. ORE   BIN  AND   HEADFRAME   FOR  A    WINZE  HOIST. 

from  or  not  connected  with  the  main  hoisting  shaft.  The  desire  to  develop 
rapidly  the  shoot  and  other  reasons  may  make  it  necessary  to  raise  more  rock  or 
ore  through  a  winze  than  can  be  handled  by  the  usual  hand-operated  windlass 
and  bucket,  and  it  becomes  necessary  to  equip  the  winze  with  a  power  hoist  and 
headframe  to  carry  the  sheave.  The  accompanying  illustration,  Fig.  108, 


i66 


HANDBOOK  OF  MINING^DETAILS 


furnished  by  Percy  E.  B arbour,  is  of  a  headframe  for  a  winze  such  as  was  de- 
signed for  use  in  the  Copper  Mountain  mine  in  Nevada.  The  design  follows 
closely  the  usual  two-post  surface  headframe,  but  is  not  so  high  nor  is  it  built 
of  as  heavy  timber  as  is  usually  deemed  necessary  for  a  surface  structure.  The 
details  are  fully  shown  in  the  illustration.  The  station  is  cut  out  as  closely  as 
possible  to  just  admit  of  the  erection  of  the  headframe  and  is,  .of  course,  prefer- 
ably situated  where  the  walls  are  strong  enough  to  require  minimum  timbering. 
While  no  guides  are  shown  in  the  illustration,  if  it  is  desirable  to  use  them  while 
sinking  with  a  bucket,  they  may  be  supported  in  the  same  manner  as  if  the  head- 
frame  were  at  the  surface.  To  receive  the  ore  and  rock  raised  and  facilitate 
the  loading  of  cars,  a  small  box-like  ore  bin  is  built  in  front  of  the  frame. 

An  Underground  Hoist. — The  accompanying  illustration,  Fig.  109,  shows 
the  method  of  arranging  the  hoisting  equipment  for  a  large  winze  that  was  sunk 


Front  Elevation  and 
Section  of  Head-gear 


FIG.  lOQ. — ARRANGEMENT  OF  AN  UNDERGROUND  HOIST. 

by  N.  T.  Tregear  for  the  Black  Mountain  Mining  Co.,  operating  a  copper  mine 
near  Magdalena,  Sonora.  The  winze  was  sunk  to  a  depth  of  400  ft.  from  the 
No.  8  tunnel  at  a  distance  of  1200  ft.  from  the  portal.  Below  the  collar  there  are 


HEADFRAMES,  CHUTES,  POCKETS,  ETC.  167 

two  compartments,  each  4  1/2X5  ft.  in  the  clear,  while  above  the  collar  there 
are  two  compartments,  each  4  1/2X5  ft-,  that  were  carried  up  to  support  the 
sheaves  and  to  obtain  head  room  above  the  tunnel  for  an  automatic  dumping 
skip  and  two  ore  pockets.  The  sheave- wheel  bearers  are  dressed  timber  111/2 
X 15  in.  and  26  ft.  long;  the  bearing  posts  are  12X12  in.  section,  as  are  also  the 
supporting  bearers  and  dividers.  The  housing  is  made  of  8X8-in.  timber; 
the  shaft  sets  are  8X8-in.,  and  the  auxiliary  dumping  set  is  of  7  1/2X11  i/2-in. 
timber;  two  of  the  collar  bearers  are  12  X  i2-in.,  and  two  8X8  in.,  and  the  guides 
are  5  1/2X5  i/2-in.  section.  The  shaft  sets  are  spaced  5-ft.  centers,  the  station 
sets  1 5  ft.  and  the  dumping  set  20  ft.  The  winze  is  lagged  with  2 -in.  lumber. 

Details  of  a  Wooden  Headframe. — In  Fig.  no  the  details  of  the  head- 
frame  of  the  Clermont  shaft  at  Goldfield,  Nev.,  are  shown.  This  is  an  excellent 
example  of  the  simple  A-frame  type  of  head  gear.  The  total  quantity  of  timber 
used  in  the  construction  of  the  headframe  was  23,000  board  feet.  There  were 
also  used  3300  Ib.  of  bolts  and  rods,  and  500  Ib.  of  cast-iron  washers. 

Overwinding  Allowance  in  Head  Gears. — In  cases  of  overwinding,  acci- 
dents frequently  happen  from  a  blow  by  the  liberated  end  of  the  rope,  and  the 
rope  itself  may  also  be  damaged.  To  prevent  this,  a  drag  rope  forms  a  useful 
auxiliary.  This  may  be  of  light  wire  rope  carried  on  a  small  light  drum  placed 
near  the  detaching  gear,  the  free  end  of  the  rope  to  be  formed  into  a  loop  of  such 
size  as  to  allow  the  hoisting  rope  to  run  through  freely,  yet  too  small  to  admit 
the  rope  capping;  this  loop  to  be  lightly  fixed  just  over  the  detaching  ring. 
When  an  overwind  takes  place,  the  freed  end  of  the  hoisting  rope  is.  at  once  held 
in  check  by  the  drag  rope.  The  drag-rope  drum  might  be  provided  with  a 
brake  or  a  coil  spring  inside,  so  as  to  prevent  the  rope  running  out  too  freely. 
The  headgear  should  be  of  sufficient  height  to  allow  for  a  fair  overwind  in  addi- 
tion to  the  working  height.  As  a  general  rule,  it  is  suggested  that  the  distance 
in  feet  from  the  underside  of  the  sheave  to  the  pin  which  connects  the  rope  to  the 
skip  or  cage  standing  at  the  point  in  which  the  journey  is  properly  completed 
should  not  be  less  than  the  average  hoisting  speed  in  feet  per  minute  divided 
by  200.  For  example,  if  the  average  hoisting  speed  be  3000  ft.  per  minute,  the 
overwinding  allowance  would  be  15  ft. 

Tipple  Construction  in  the  Birmingham  District. — The  tipples  used  by 
the  Tennessee  Coal,  Iron  &  R.  R.  Co.  and  the  Republic  Iron  Co.  at  the  slopes 
of  their  iron-ore  mines  on  Red  Mountain,  Alabama,  are  different  from  those  seen 
at  any  other  slopes  in  the  Birmingham  district.  These  companies  hoist  in  10- 
ton  skips,  whereas  most  of  the  other  companies  use  trains  of  five  2 -ton  cars. 
The  constructional  details  of  the  tipples  at  a  slope  on  the  Muscoda  division  of 
the  Tennessee  company's  ore  mines  are  indicated  in  Fig.  in.  The  slope 
entry  is  not  perpendicular  to  the  main  railroad  loading-track  below  the  tipple, 
this  accounting  for  the  angle  at  which  the  Nos.  i  and  2  bents  are  placed.  The 
tipple  carries  two  sets  of  tracks  one  above  the  other.  The  upper  one,  set  at 
6-ft.  gage,  engages  the  rear  wheels  of  the  skip,  thus  elevating  it  into  the  position 


i68 


HANDBOOK  OF  MINING  DETAILS 


HEADFRAMES,  CHUTES,  POCKETS,  ETC. 


169 


© 


-  Q-. 


170  HANDBOOK  OF  MINING  DETAILS 

of  dump  shown  by  dotted  line.  The  front  wheels  follow  the  lower  tracks  which 
are  set  at  the  regular  5-ft.  spacing.  The  door  of  the  skip  is  hinged  at  the  top 
and  held  tightly  closed  during  hoisting,  by  the  bale  of  the  skip.  When  the  rear 
of  the  skip  is  raised  the  bale  swings  up  and  allows  the  door  to  open  and  the  load 
to  discharge.  The  ore  is  dumped  into  a  bin  holding  about  150  tons  and  made 
long  enough  at  the  top  so  that  the  skip  will  not  have  to  be  dumped  within  close 
confines  in  order  to  discharge  entirely  within  the  bin.  The  ore  bin  is  built  with 
double  planking  on  bottom  and  sides  and  is  9  ft.  wide,  about  26  ft.  deep  at 
No.  3  bent  and  has  slopes  to  the  bottom  of  40  and  38°,  as  shown  in  drawing. 
This  insures  that  the  ore  will  feed  freely  to  the  gyratory  crusher,  which  is  set 
on  a  concrete  base,  between  No.  2  and  3  bents.  The  crusher,  a  No.  8  Austin, 
delivers  its  product  directly  into  railroad  cars  which  are  let  down  the  track  by 
gravity.  Details  of  the  framing  of  the  bents,  five  of  which  are  used  in  this  par- 
ticular tipple,  are  shown  fully  in  the  drawing.  They  are  framed  from  12X12 
timbers  battered  3  in.  to  i  ft.  and  cross  braced  with  3X10  plank.  The  bents  are 
set  on  concrete  bases.  The  details  of  the  corbels  of  the  No.  2  bent  are  also 
given  in  the  cut.  This  construction  gives  a  strong  and  satisfactory  tipple  at  a 
not  too  excessive  first  cost.  The  Tennessee  company  uses  these  wooden  tipples 
at  all  of  its  ore  mines  on  Red  Mountain,  but  the  Republic  company  has  substi- 
tuted steel  construction  for  the  wooden  type.  The  general  form  of  tipple,  how- 
ever, is  retained. 


ORE  BINS 

•  Cananea  Ore  Bins  (By  Claude  T.  Rice). — The  drawings  given  in  Fig.  112 
show  the  standard  bin  construction  that  has  been  adopted  at  the  mines  at 
Cananea,  Mexico.  The  bin  has  a  bottom  sloping  at  45°,  and  the  inside  is  lined 
with  sheet  iron  3/16  in.  thick,  in  which  the  holes  for  the  nails  are  countersunk. 
This  slope  at  the  bottom  has  been  found  sufficient  for  the  Cananea  ores,  but  it  is 
well  when  building  bins  with  a  sloping  bottom  to  bear  in  mind  that  heavy 
sulphide  ores  of  copper  when  coming  damp  from  the  mines  are  apt  to  pack  in  a 
bin  having  a  bottom  slope  of  45°.  Such  was  the  experience  at  the  new  ore  bins 
built  at  the  Highland  Boy  mine  at  Bingham  for  the  use  of  consolidated  tramways, 
and  I  understand  that  such  also  was  the  experience  with  some  of  the  heaviest 
ores  at  the  Cerro  de  Pasco  mines  in  Peru.  In  a  bin  with  a  sloping  bottom  the 
weight  is  practically  all  thrown  on  the  front  posts,  so  at  Cananea  it  is  the  prac- 
tice to  use  double  front  posts.  When  a  bin  is  designed  it  is  the  custom  at 
Cananea  to  lay  out  the  plan  of  the  sheet-iron  lining,  so  that  when  the  construc- 
tion is  ordered  the  plans  can  be  taken  to  the  machine  shop,  and  the  lining  be 
prepared  and  marked,  ready  for  putting  in  place  in  the  bin.  By  planning  the 
details  in  advance  and  having  all  parts  ready,  costly  delays  in  the  erection  of  the 
bins  are  avoided. 

Tonopah  Orehouses. — In  the  orehouses  at  Tonopah  special  provision  is 


HEADFRAMES,  CHUTES,  POCKETS,  ETC. 


171 


— 


1 


/ /   "  5  ' 
/    g  =  I 


x  01 


L 


172 


HANDBOOK  OF  MINING  DETAILS 


§>      o 
*     -  -H     u 


ni-n  x  r.I  in  CQ  /n5-9  x  9    -ni-r,I  x  si  -d    ._, 


HEADFRAMES,  CHUTES,  POCKETS,  ETC.  173 

made  for  sorting  the  ore.  The  drawings  shown  in  Fig.  113  give  the  details  of 
construction  of  the  new  bins  at  the  Red  Plume  and  the  Silver  Top  shafts,  which 
were  designed  by  J.  M.  Fox,  while  assistant  superintendent  for  the  Tonopah 
Mining  Co.  The  older  bin  of  the  Mizpah  orehouse  was  built  with  a  sloping 
bottom,  but  that  form  is  not  so  cheap  in  the  first  cost,  and  also  requires  great 
expenditure  to  keep  it  in  repair. 

The  Silver  Top  and  the  Red  Plume  orehouses  required  from  43,000  to 
45,000  board  feet  in  their  construction,  and  as  they  had  flat  bottoms,  the  only 
protection  required  was  a  small  amount  of  sheet  iron  around  the  mouths  of  the 
gates.  The  capacity  of  each  bin  is  about  450  tons.  The  cost  was  between 
$5000  and  $6000  each  completed,  with  Oregon  spruce  at  $37.50  per  thousand, 
and  erection  done  by  contract  in  a  camp  where  carpenters  earn  from  $5  to  $5.50 
per  8-hour  shift.  The  upkeep  for  the  last  two  years  has  been  practically  nothing. 

The  Mizpah  orehouse  has  a  bottom  sloping  at  40°,  so  that  it  has  to  be 
protected  with  a  sheet-iron  covering.  It  took  110,000  board  feet  to  build  that 
orehouse  and  the  capacity  is  between  400  and  450  tons.  As  ihe  orehouse  was 
erected  early  in  the  life  of  the  camp  when  the  cost  of  materials  was  excessive, 
it  would  not  be  fair  to  use  the  actual  cost  in  a  comparison.  However,  it  costs 
two  and  one-half  times  as  much  to  build  a  sloping-bottom  bin  as  one  with  a  flat 
bottom.  One  of  the  commendable  features  of  the  Tonopah  orehouses  is  that 
the  grizzlies  are  placed  so  that  the  ore  is  dumped  against  instead  of  with  the 
slope.  This  insures  a  better  screening  action  on  the  grizzlies.  In  order  to 
sample  the  fines  from  the  grizzlies  a  3-in.  channel  iron  is  carried  underneath 
clear  across  the  grizzlies  and  at  right  angles  to  the  bars,  but  at  an  angle  of 
between  30  and  35°  from  the  horizontal,  so  that  the  fines,  which  are  caught 
in  the  channel  sampler  after  falling  through  the  grizzly  openings,  i  1/2  in. 
wide,  slide  down  into  a  sample  box  on  the  floor  of  the  orehouse. 

Besides  the  economy  with  which  the  timber  has  been  used  in  the  erection  of 
the  bin,  a  leading  feature  of  the  construction  is  the  commodious  arrangement 
of  the  upper  part  so  as  to  facilitate  the  sorting  of  the  ore.  The  oversize  from 
the  grizzlies  runs  into  a  small  upper  ore-pocket,  having  feed  holes  at  the  bottom 
which  permit  the  ore  to  run  out  by  gravity  upon  the  sorting  tables  as  sorting 
progresses.  Consequently,  the  ore  with  only  a  little  scraping  is  in  a  thin  layer 
in  front  of  the  ore  sorters  so  that  they  can  quickly  throw  the  pieces  of  waste  into 
a  mine  car  on  a  track  nearby,  while  the  ore  can  be  easily  scraped  into  holes  in 
the  floor  that  lead  to  the  ore  bin  proper.  These  openings  are  so  placed  that  a 
man  cannot  easily  walk  into  them. 

The  Tonopah-Belmont  orehouse  is  noteworthy  for  the  novelty,  at  least  in 
metal  mining,  of  the  manner  of  constructing  the  ore  bins,  which  is  quite  similar 
to  some  of  the  bins  that  have  been  built  at  eastern  cement  works.  The  floor  of 
the  bin  is  carried  on  a  series  of  separate  inner  posts,  while  the  outside  posts, 
against  which  the  bottom  beams  abut,  extend  to  the  top  of  the  bin  and  serve  as 
binding  posts,  as  it  were,  to  give  stability.  The  accompanying  elevations  and 


174 


HANDBOOK  OF  MINING  DETAILS 


sections  (Figs.  114  and  115)  show  the  details  of  this  type  of  construction.  The 
sorting  shed  construction  is  quite  similar  to  the  arrangement  in  the  orehouses  of 
the  Tonopah  Mining  Co.,  except  that  instead  of  the  ordinary  bar  construction 
of  the  grizzlies,  they  are  made  of  cast-steel  plates  i  in.  thick  with  bored  holes 
2  in.  in  diameter  at  the  top  and  2  in.  at  the  bottom  face,  arranged  in  staggered 
holes  and  with  plates  set  at  an  angle  of  40°,  at  which  they  clear  themselves  well. 
The  ore  hoppers  above  the  sorting  tables  are  lined  with  steel. 

In  the  construction  of  the  orehouse  73,000  board  feet  of  lumber  was  used. 
The  bin  has  a  capacity  of  about  750  tons,  being  divided  into  three  compartments, 

Detail  Sections 
Cop  Joint 


Through  C-C  Through  A-A  Through  B-B 

Left  Chute,  Bin  and  Upper  Floors,  through  C-C 
Center  Chute,  through  A-A 
Section  through  E-E  Right  Chute,  through  B-B 

FIG.    114. — SECTIONS    OF   TONOPAH-BELMONT   OREHOUSE. 

two  of  10,000,  and  the  other  of  about  5000  cu.  ft.  capacity.  The  structure  is 
51  ft.  long  by  28  ft.  wide  by  64  ft.  high  to  the  top  of  the  ridge  pole.  The  main 
sill  timbers  are  bolted  to  massive  concrete  mud-sills,  while  the  bin  is  supported 
on  seven  bents  of  four  posts  1 2  X 1 2  in.  each.  The  outer  posts  reach  from  sill 
to  top  of  bin,  while  the  inner  line  of  posts  support  the  longitudinal  caps  on  which 
the  bin  floor  rests.  This  floor  is  made  of  3  X  8-in.  planks  placed  on  edge,  and  is 
continuous  across  the  whole  width,  with  the  outer  ends  resting  on  girts  that  are 
framed  into  the  outer  post.  To  increase  the  stability  of  the  bin  the  girts  and 
long  posts  are  heavily  reinforced  by  8X  i2-in.  cleats  and  sway  braces. 


HEADFRAMES,  CHUTES,  POCKETS,  ETC. 


175 


The  sides  of  the  bin  are  made  of  a  double  lining  of  2X  i2-in.  planks,  with 
joints  broken,  while  the  partitions  also  are  made  of  2-in.  planks.  There  are 
six  steel-lined  loading  chutes,  three  on  each  side  of  the  track.  These  are  fitted 
with  No.  3  Bolthoff  lever  gates,  with  movable  steel  spouts.  A  clearance  space 
of  1 8  ft.  is  provided  above  the  rails,  so  that  a  locomotive  can  go  under  the  bin. 
Above  the  bin  the  orehouse  part  is  covered  with  galvanized,  corrugated  iron. 

Concrete  Storage  Bin  (By  Fremont  N.  Turgeon). — A  reinforced-concrete 
storage  bin,  interesting  for  its  size,  ease  of  construction  and  cheapness,  is  at  one 
end  of  Witherbee,  Sherman  &  Co.'s  new  magnetic-concentrating  mill,  at  Mine- 
ville,  N.  Y.  It  is  circular  in  section,  25  ft.  in  outside  diameter,  and  45  ft.  high. 


End  Elevation  Side  Elexation 

FIG.    115. — ELEVATIONS   OF  TONOPAH-BELMONT  OREHOUSE. 

It  has  a  capacity  of  1500  tons  of  crude  ore,  of  which  about  1000  tons  will  run 
out  without  handling.  The  foundation  is  of  rough  uncrushed  mine  stone 
bonded  together  with  a  lean  mixture  of  tailings  and  cement  in  the  ratio  of  10  :  i. 
The  walls  are  18  in.  thick  at  the  bottom,  and  decrease  2  in.  in  thickness 
every  9  in.  up  to  the  top,  which  is  10  in.  in  thickness.  The  mixture  of  the  walls 
is  4:1,  tailings  and  cement.  The  reinforcing  is  wornout  steel  hoisting 
cable,  i  1/8  in.  in  diameter,  spaced  as  shown  in  Fig.  116.  The  ends  of  each 
hoop  of  cable  are  fastened  together  with  old  cable  grips.  Vertical  cables  are 


i76 


HANDBOOK  OF  MINING  DETAILS 


placed  every  4  ft.  about  the  circumference  and  anchored  in  the  foundation,  and 
the  hoop  cables  are  fastened  to  each  vertical  cable  with  ties  of  old  bell  wire,  and 
are  placed  4  in.  from  the  outside  circumference. 

The  forms  were  i-in.  matched  boards  nailed  to  circular  forms  cut  from  2-in. 
plank,  spaced  every  4  ft.  vertically,  and  supported  by  short  studs  from  the  set 
below.  The  entire  outside  form  was  made  first,  then  the  reinforcing  put  in  and 
fastened  and  supported  on  the  outside  form,  the  work  being  done  from  a  staging 
inside  the  bin ;  then  the  first  9  ft.  of  inside  form  was  put  in  and  tied  to  the  outside 
form  with  i/2-in.  tie  rods,  and  the  walls  cast.  On  top  of  this  the  next  9  ft.  of 


- 


12"  -o 


14" 


16'" 


1 


I 


VW/y////tyy/;///////r7/>///>//////;;;////////////77^ 
FIG.    Il6. — CONCRETE   STORAGE   BIN,    MINERVILLE,    N.    Y. 

form  was  erected  and  the  walls  cast,  and  so  on  to  the  top.  The  concrete  was 
raised  by  an  elevator  to  the  level  of  the  top  of  the  form  being  cast,  and  carried 
to  the  form  by  wheelbarrows  through  a  small  door  in  the  outside  form  which 
was  subsequently  closed.  The  walls  of  the  bin  are  thicker  than  necessary,  to 
allow  for  the  wear  of  the  ore  sliding  down,  as  the  bin  is  emptied  daily.  As  may 
be  seen,  all  ore  does  not  run  out  naturally.  To  overcome  this,  before  being 
used  the  bin  was  filled  with  crushed  barren  material  until  it  ran  out  of  the  door, 
and  ore  was  put  in  on  top  of  this. 


VIII 

HOISTING  AND  TRANSPORTATION 

Theoretical  Considerations — Notes  on  Practice — Hoists — Miscellaneous 
Devices — Aerial  Tramways. 

THEORETICAL    CONSIDERATIONS 

Graphic  Solution  of  Skip  Loads  (By  F.  W.  Collins). — The  pull  on  the  bail 
of  a  skip  used  in  an  incline  shaft  and  the  load  on  the  wheels  can  be  determined 
graphically  by  the  method  illustrated  in  Fig.  117.  In  the  sketch  6  is  the  angle 


FIG.    117. — GRAPHIC   DETERMINATION   OF   PULL   ON  A   SKIP  BAIL. 

of  inclination  of  the  shaft;  AH,  a  vertical  line  drawn  through  the  center  of 
gravity  of  the  skip;  AG  is  the  center  line  of  the  front  wheel  drawn  normal  to  the 
rail;  EF,  the  center  line  of  the  rear  wheel  drawn  normal  to  the  rail;  E  is  the  point 
of  intersection  of  EF  with  the  center  line  of  the  bail;  A  is  the  point  of  intersection 
of  AH  with  AG,  the  center  line  of  the  front  wheel.  After  completing  this  con- 
struction lay  off  on  AH  the  distance  AD,  the  weight  of  the  skip  and  load,  to  any 
convenient  scale,  and  draw  BD,  parallel  to  AG,  and  BC,  parallel  to  the  center 
line  of  the  bail;  then  BD  will  be  the  load  on  the  front  wheels,  BC  the  pull  on 
the  bail,  and  AC  the  load  on  the  back  wheels.  The  bail  need  not  be  parallel 
to  the  rails  and  may  be  hinged  at  any  point. 

Vertical  Unbalanced  Loads  Lifted  by  First  Motion  Hoists. — The  ac- 
companying charts  were  prepared  by  L.  F.  Mitten  of  the  Vulcan  Iron  Works, 
12  177 


HANDBOOK  OF  MINING  DETAILS 


i78 

Wilkesbarre,  Penn.     The  first,  reproduced  in  Fig.   118,  is  plotted  from  the 
following  formula: 

Load= 


3.1416!) 

P=  Initial  pressure  at  the  throttle. 
A  —  Area  of  cylinder. 
L=  Stroke  in  feet. 
D=  Diameter  of  winding  drum  in  feet. 


Diameter  Drum  in  Feet. 


Vertical  Unbalanced  Loads 

Lifted  by 

First  Motion  Engines 

at 

Various  Steam  Pressures 

with 

Drums  from  4'  to  12'Diameter. 


Based  on  Initial  Pressure  at  the  Throttle, 
and  One  Cylinder  only  being  Operative. 


Diameter  Cylinder  Steam  Pressure.  Diameter  Drum  in  feet. 

FIG.    Il8. — CHART   FOR   FINDING   THE   PROPER-SIZED    ENGINE   WHEN   THE    UNBALANCED    LOAD 
AND   THE    STEAM   PRESSURE   ARE    KNOWN. 

Either  cylinder  of  the  pair  of  engines  is  capable  of  starting  the  unbalanced 
load  given,  inasmuch  as  one  cylinder  may  be  on  a  dead  center  and  would  there- 
fore be  inoperative.  The  steam  pressure  is  taken  at  the  full  initial  pressure  at 
throttle.  An  efficiency  of  85  %  has  been  taken,  this  having  been  found  after 
various  tests  to  be  a  fair  average. 


HOISTING  AND  TRANSPORTATION 


179 


Knowing  the  unbalanced  load  and  the  steam  pressure  at  the  throttle,  the 
proper-sized  engine  for  the  work  may  be  found  without  any  figuring  whatever. 
It  will  also  be  readily  seen  that,  having  the  size  of  the  engine  cylinders,  the 


-7    /-   / 


3500 


S2500 


eet 


BOO 


£S 


+///// 


ti 


ii  •> 


Rev 
1! 


utions  per  Minute, 
)  2(0 


250 


90 


100 


200 


300 


400 


m 


m 


70° 


800 


900 


1000 


UOO 
1200 


^ 


\ 


i 


^. 


V  M  \N 


\DZSK 


x^. 


\ 


t> 


FIG.    IIQ. — CHART   FOR   DETERMINING   THE   ROPE   SPEED    IN  HOISTING. 

vertical  load  that  can  be  lifted  by  them  may  also  be  found  for  any  steam  pressure 
and  various  diameters  of  drum. 

As  an  example,  find  the  size  of  engine  capable  of  handling  a  vertical  unbal- 


i8o 


HANDBOOK  OF  MINING  DETAILS 


anced  load  of  12,000  Ib.  with  loo-lb.  steam  pressure  at  the  throttle.  The  rope 
manufacturers  give  the  working  load  for  i-in.  rope  as  6.8  tons.  However,  in 
actual  practice,  for  this  load  a  i  i/4-in.  rope  would  probably  be  used  and  wound 

Rope  Speed  in  Feet  per  Minute. 

§  1 1 1  §  s  s  i  rit  1 1 1  fi  i  1 1  i 


Allowance  for  Changing  Cars  or  Dumping  same  =  15  Seconds. 
FIG.    120. — CHART  TO  DETERMINE   NUMBER   OF  CARS  HOISTED   PER  HOUR. 
Capacity  in  Feet  per  Foot  of  Face.    Straight  Face  Grooved  Drums. 

100  WO  120  130  140  150  160  170  180  100  200  210  220  230  240  250  260  270  230  200  300  310  320  330  340  350  360  370 


13' 0 


FIG.    121. — CHART  FOR  DETERMINING  THE   FACE   OF  A   GROOVED   DRUM. 

on,  say,  an  8-ft.  diameter  drum.  Follow  the  horizontal  line  marked  12,000 
until  it  is  intersected  by  the  diagonal  line  at  or  about  the  vertical  line  rep- 
resenting an  8-ft.  diameter  drum;  then  follow  the  diagonal  line  down  to  left  side 


HOISTING  AND  TRANSPORTATION 


181 


of  chart;  follow  horizontal  line  across  until  it  is  intersected  by  diagonal  line  at 
or  about  the  line  representing  loo-lb.  steam  pressure;  follow  this  diagonal  line 
as  previously  described  to  left  side  of  chart;  follow  horizontal  line  until  proper 

Capacity  in  Feet  per  Foot  of  Face.   Drum  not  Grooved. 

100  110  120  130  HO  150  160  170  180  190  200  210  220  230  240  250  260  270  280  290  300  310  320  330  340  350  360  370  380 


13'0 


12'0' 

n'c" 


3*0" 


FIG.  122. CHART  TO  DETERMINE  THE  FACE,  WHEN  THE  DRUM  IS  NOT  GROOVED. 

Capacity  in  Feet  per  Foot  of  Face.    Conical  Grooved  Drums. 

100  110  120  130  140  150  160  170  180  190  200  210  220  230  240  250  260  270  280  290  300  310  320  330  340  350  360  370  380 


13*0" 
12'6" 
12'  0" 

n'e" 

11'  0" 

io'e" 

lO'O" 

1   9'0" 
Q   8*6" 
«  8'0" 
I   7'"" 

C'6" 

e'o" 

sV 

5'0" 
4'6" 
4'0" 

S'e" 

3'0" 

FIG.  : 

^ 

^  ^ 

? 

/ 

x 

x 

x 

x 

x 

.. 

x 

/  , 

/ 

^ 

f 

/ 

x 

x 

x 

^ 

x 

X 

X 

/ 

^ 

/ 

/ 

x 

X 

x 

x 

x 

x 

X 

•^ 

~t 

/ 

/ 

> 

s 

X 

x 

x 

X 

^ 

x 

x 

^ 

x 

s 

/ 

/ 

.x 

? 

x 

x 

X 

x 

X 

^ 

| 

B 

/ 

x 

/ 

? 

y 

? 

.X 

^ 

x 

x 

x 

x^ 

X 

/ 

^/ 

X 

X 

1 

x 

x 

x 

x 

X 

X 

X1 

^^ 

X 

/ 

/ 

J 

vX 

' 

X 

X 

x 

^ 

X 

x 

-x"" 

/ 

V 

/ 

x 

x;v 

^,0^ 

X 

• 

x 

x 

X 

xx^ 

x 

•^ 

// 

> 

/ 

/ 

x 

x 

3 

^> 

^ 

x 

?r 

X 

^ 

x^ 

x/ 

/ 

/ 

x 

/ 

X 

'   x 

x 

fer 

s 

X 

x 

x^^ 

x 

// 

X 

x 

x 

/ 

x 

/ 

x 

pg.^5j^ 

^x- 

*J 

/ 

*/\/ 

X 

x 

x 

x 

x 

x 

x] 

•x^1 

^ 

X 

// 

XX 

x 

x 

X 

x 

' 

X 

, 

x 

x 

'  / 

x 

x, 

x 

x 

x 

X 

•^ 

X 

x^ 

X' 

•^ 

'  / 

x. 

x 

x, 

x 

x 

x 

x^ 

/> 

x, 

x  . 

x 

x 

x 

x^ 

x 

•X- 

''x 

x  ^ 

x1 

^ 

^^ 

X 

X 

^^ 

x 

x 

x 

x^ 

x 

' 

[23.  —  CHART  TO  DETERMINE  THE  FACE   OF  A  CONICAL  DRUM;  THE  DIAMETER   SHOULD  BE 

THE  MEAN  DIAMETER. 


combination  of  stroke  and  diameter  are  found.  For  the  work  in  hand  the 
following  engines  would  be  satisfactory:  24X48  in.  or  28X36  in.;  the 
24X48-in.  size  would  probably  be  selected. 


182 


HANDBOOK  OF  MINING  DETAILS 


Determining  the  Rope  Speed  in  Hoisting. — In  determining  the  rope 
speed  in  a  hoisting  operation  when  the  average  piston  speed,  the  length  of  stroke 
and  diameter  of  drum  are  known,  the  second  chart  (Fig.  119)  provides  a  handy 
method  of  calculation.  As  an  example,  let  us  assume  an  average  piston  speed 
of  600  ft.  per  minute,  and  a  48-in.  stroke;  then,  following  the  horizontal  line  on 
the  chart  at  600  until  it  is  intersected  by  the  diagonal  line  representing  a  48-in. 
stroke,  follow  this  line  to  the  upper  section  until  it  is  intersected  by  the  diagonal 
line  representing  an  8-ft.  drum;  by  following  the  horizontal  line  to  the  side  of  the 
chart  the  rope  speed  is  found  to  be  1890  ft.  per  minute. 


Diagram  showing  Amount-  of 

Rope  Wound  on  Drums  of  various 

Diameters  and  Faces. 


FIG.  124. 

Determining  the  Number  of  Cars  Hoisted  per  Hour.— The  third  chart  of 
the  series  enables  the  quick  calculation  of  "cars  per  hour,"  when  depth  of  shaft 
and  certain  other  factors  are  known.  As  an  example,  assume  the  shaft  is  475  ft. 
deep,  and  a  rope  speed  of  1900  ft.  By  referring  to  Fig.  120,  it  will  be  readily 
seen  that  from  a  shaft  475  ft.  deep  we  can  get  out  two  cars  per  minute,  or  120 
cars  per  hour.  This  chart  is  based  on  an  allowance  of  one  quarter  of  a  minute 
for  changing  cars  and  a  double-compartment  shaft. 


HOISTING  AND  TRANSPORTATION 


183 


Determining  the  Face  of  Winding  Drums. — In  determining  the  face  of 
winding  drums  when  the  diameter  of  the  drum  and  the  rope  diameter  are  known, 
the  charts  reproduced  in  Figs.  121,  122,  and  123  will  be  found  useful. 

Assume  that  the  drum  has  a  diameter  of  8  ft.,  and  that  the  rope  diameter  is 
i  1/4  in.;  also  that  the  shaft  is  475  ft.  deep;  then  referring  to  Fig.  121  it  is  found 
that  an  8-ft.  diameter  drum  will  wind  227  ft.  per  foot  of  face.  The  drum 
required  would  therefore  have  to  be,  say,  2  ft.  6  in.  face,  which  would  allow  a 
sufficient  number  of  grooves  at  one  end  of  drum  for  fastening  the  rope. 

The  other  charts  shown  in  Figs.  122  and  123  would,  of  course,  be  used  in 


Diagram  showing  Power  Required  to  Haul  Cars  on  Various  Pitches. 

Note:-  Shaded  Portions  on  Pitch  Diagonals  show  Amouut  to  be  Added  for  Rolling  Friction, 
varying  from  50  Lbs.  per  Ton  on  the  Level  to  5  Lbs.  on  Vertical  Lift, 
lower  for  Rope  is  Worked  separately  and  Added  to  Power  for  Cars. 
Equivalent  Pull  on  Rope  doe  to  Load  on  the  Plane. 


Pitch  of  Plane  in  Per  cent,  or  Rise  in  Feet  per  100  Ft.  Horizontal. 
FIG.   125. 

the  same  manner  as  illustrated  above.     The  diameter  used  for  conical  drums, 
however,  should  be  the  mean  diameter. 

Determining  the  Amount  of  Rope  Wound  on  a  Drum.— In  determining 
the  amount  of  rope  wound  on  drums  of  various  diameters  and  faces,  the  chart 
given  in  Fig.  124  provides  a  quick  method  of  calculation.  It  is,  of  course, 
essential  that  the  circumference  and  diameter  of  the  drum  are  known.  The 


184  HANDBOOK  OF  MINING  DETAILS 

chart  also  assumes  that  the  face  of  the  drum  is  a  known  quantity.  With  these 
factors  at  hand,  the  method  of  calculation  is  self-evident. 

Power  Required  to  Haul  Cars  on  Various  Pitches. — The  sixth  chart, 
reproduced  in  Fig.  125,  is  intended  to  simplify  the  calculations  for  determining 
the  power  required  to  haul  loads  on  planes  of  various  pitches.  For  example,  it 
is  desired  to  haul  two  loaded  cars,  each  weighing  6000  lb.,  up  a  plane  1000  ft. 
long,  having  a  pitch  of  40°  from  the  horizontal,  at  a  maximum  rope  speed  of 
500  ft.  per  minute.  What  is  the  equivalent  rope  pull  ?  What  is  the  brake  horse- 
power required  to  handle  the  load?  Two  loaded  cars  weighing  6000  lb.  each 
equals  a  load  of  12,000  lb.  exclusive  of  winding  rope.  Referring  to  the  diagram, 
follow  the  horizontal  line  representing  12,000  on  the  chart  until  it  is  intersected 
by  the  diagonal  line  representing  40°.  Directly  above  this  point  of  intersection 
will  be  found  the  rope  pull,  which  in  this  case  is  7900  lb.  It  is  also  found  that  a 
3/4-in.  rope  will  be  satisfactory  and. that  this  size  rope  weighs  0.88  lb.  per  foot. 
Following  down  this  imaginary  line  representing  7900  lb.  until  it  is  intersected 
by  the  diagonal  line  representing  500  ft.  per  minute  rope  speed,  one  finds  120  h.p. 
applied  to  the  load,  or  the  brake  horsepower  required.  The  horsepower  to  be 
delivered  by  this  hoist  motor  would  be  141 ;  this  is  based  on  an  efficiency  of  85  % 
for  the  entire  equipment.  It  has  been  found  that  a  3/4-in.  rope  would  be  re- 
quired and  also  that  this  size  rope  weighed  0.88  lb.  per  foot;  1000  ft.  of  rope  at 
0.88  lb.  equals  880  lb.  By  working  this  out  as  was  done  for  the  loaded  cars,  it 
is  equivalent  to  9  h.p.,  which  should  be  added  to  the  141  h.p.,  making  a  total  of 
150  h.p. 

Rope  Capacity  of  Drums. — The  rule  used  by  the  A.  Leschen  &  Sons  Rope 
Co.  for  computing  the  rope  capacity  of  any  size  of  drum,  is  as  follows:  Add  the 
depth  of  flange  in  inches  to  the  diameter  of  the  drum,  and  multiply  this  result 
by  the  out  to  out  width  of  the  drum.  This  product  is  then  multiplied  by  the 
figure  below  corresponding  to  the  size  of  the  rope  used: 

i  in 4.16  if  in o.  138 

f  in i .  86  i£  in o .  1 16 

fs  in 1.37  T|  in 0.099 

\  in i  .05  if  in 0.085 

i9g  in 0.828  if  in 0.074 

fin 0.672  2  in o.  066 

f  in 0.465  z\  in 0.058 

£  in 0.342  ai  in 0.052 

i     in o .  262  2f  in o .  046 

1 1  in o.  207  2^  in 0.042 

\\  in o.  167 

This  rule  applies,  of  course,  to  a  drum  on  which  the  rope  is  to  be  wound  in 
successive  layers  up  to  the  full  height  of  the  flange. 

NOTES  ON  PRACTICE 

Flat  Rope  vs.  Round  Rope. — A  correspondent  asks  about  the  comparative 
results  in  practice  of  flat  and  round  wire  ropes.  He  says  that  he  has  had  the 
best  results  from  the  flat  rope,  and  considers  it  the  safer  because  of  being  open  to 


HOISTING  AND  TRANSPORTATION  185 

closer  inspection.  His  superintendent  contends,  however,  that  round  cable  is 
the  better,  and  cites  Lake  Superior  and  South  African  practice.  Our  corre- 
spondent asks,  What  are  the  manufacturers'  claims?  With  respect  to  this  matter 
a  leading  manufacturer  of  wire  rope  informs  us  that  flat  rope  is  now  used  only 
in  exceptional  cases,  there  being  but  little  demand  for  it,  owing  to  its  greater 
cost. 

The  effect  of  wear  in  round  wire  rope  shows  first  in  the  outer  layers,  and  any- 
thing radically  wrong  can  therefore  be  readily  detected.  Round  wire  rope  ex- 
poses less  surface  to  atmospheric  oxidation  than  flat  rope,  and  the  core  wires, 
which  are  saturated  with  grease,  are  less  likely  to  suffer  from  oxidation  or  cor- 
rosion from  the  action  of  water,  and  especially  water  containing  acid,  so  that 
as  far  as  safety  is  concerned  round  rope  is  considered  to  be  superior  to  flat  rope. 
The  superiority  of  round  rope  in  point  of  safety  is  generally  recognized  by 
engineers.  This  explains  why  round  rope  is  so  generally  used  at  Lake  Superior 
and  in  South  Africa.  Some  engineers  go  so  far  as  to  say  that  the  use  of  flat  rope 
ought  to  be  forbidden.  A  round  rope  may  have  a  good  many  broken  wires  and 
still  be  safe,  owing  to  the  tight  binding  of  this  kind  of  construction ;  whereas  in 
flat  ropes  the  binding  is  much  looser  and  broken  wires  quickly  become  a  serious 
danger. 

Remarks  on  Hoisting  Ropes. — The  latest  Prussian  statistics  on  shaft 
hoisting  ropes  were  exhaustively  and  critically  discussed  by  Professor  Herbst, 
of  Aix-la-Chapelle,  in  a  series  of  articles  in  Gluckauf.  His  general  conclusions 
are  as  follows:  The  protective  effect  of  lubrication  ha-  not  been  plainly  proved 
in  dry  shafts.  This  observation  suggests  that  the  present  lubrication  processes 
for  wet  ropes  leave  room  for  improvement,  although  it  is  certain  that  all 
now-known  lubricative  agents  rapidly  disintegrate  m  shafts  where  the 
water  is  salty  or  sour.  Future  experiments  in  this  direction  may  provide  a 
remedy.  Galvanizing  or  coating  with  zinc  does  not  appear  to  have  a 
really  protective  effect  in  wet  shafts,  the  reason  probably  being  that  zinc 
coating  has  but  little  power  of  resistance  to  salt  water.  It  is  also  suggested  that 
the  wires  have  suffered  in  the  galvanizing  process,  for,  although  it  has  been 
proved  by  Winter  and  others  that  the  process,  when  properly  and  carefully 
executed,  does  not  unfavorably  affect  the  ropes,  it  is  also  well  known  that 
it  often  reduces  the  tensile  strength  of  the  rope  by  50%  or  more.  The 
hauling  efficiency  of  ropes  in  dry  shafts  stands  in  the  proportion  of  100  to  60  or 
70  to  that  in  wet  shafts,  a  fact  which,  in  view  of  the  high  price  of  ropes,  means  a 
substantial  economic  advantage  for  dry  shafts.  Tensile  strength  between  160 
and  1 80  kg.  per  square  millimeter  does  not  unfavorably  affect  the  flexibility 
or  hauling  strength  of  the  ropes,  while  ropes  of  more  than  180  kg.  per  square 
millimeter  have  given  substantially  lower  efficiency  figures.  The  greater  or 
less  strain,  as  expressed  by  a  higher  or  lower  safety  factor,  put  upon  ropes  has 
had  no  influence  upon  their  consistency.  It  may,  therefore,  be  assumed  that 
the  advantages  of  a  higher  factor  of  safety  are  neutralized  by  its  disadvantages 


l86  HANDBOOK  OF  MINING  DETAILS 

that  is,  greater  rope  thickness  combined  with  reduced  flexibility  and  greater 
dead  weight. 

Uses  for  Old  Hoisting  Cable.— As  old  hoisting  cable  has  had  most  of  the 
stretch  taken  out  of  it,  it  makes  good  reinforcement  for  concrete  work.  At  the 
Red  Jacket  shaft  of  the  Calumet  &  Hecla  company  old  hoisting  cable  is  un- 
stranded  and  the  strands  are  also  used  on  the  underground-haulage  systems 
for  the  wearing  ropes.  In  removing  the  grease  from  the  cable,  burning  was 
tried,  but  it  took  the  temper  out  of  the  wires  and  the  strands  would  untwist,  so 
now  only  a  part  of  the  grease  is  taken  off  the  cables  before  they  are  unstranded. 

The  unstranding  is  done  in  lengths  of  600  ft.  A  block  and  tackle  is  fastened 
to  each  end  of  the  cable  and  it  is  stretched  so  that  it  will  be  clear  of  the  ground. 
In  attaching  the  blocks  to  the  cable  a  clamp  is  used  consisting  of  a  bar  with  a 
hinged  top  piece  which  is  tightened  on  the  rope  by  a  bolt  at  the  other  end.  The 
block  and  tackle  at  each  end  is  fastened  to  a  swivel  so  that  the  cable  can  twist  in 
either  direction  as  it  is  being  unstranded.  Two  strands  are  unstranded  at  a 
time  and  each  of  these  strands  is  fastened  to  a  block  so  that  they  can  be  kept  tight 
as  they  are  being  unstranded.  These  blocks  are  fastened  at  some  distance  from 
each  other  as  well  as  from  the  main  cable,  so  that  neither  one  of  them  will  inter- 
fere with  either  the  other  or  the  main  rope  while  it  is  being  unstranded. 

About  2000  ft.  of  cable  can  be  unstranded  in  a  day,  and  about  12,000  ft.  of 
single-strand  rope  obtained.  Both  i-in.  and  y/8-in.  hoisting  rope  has  been 
unstranded  for  the  haulage  systems.  This  old  rope  has  been  found  to  work 
quite  satisfactorily  for  the  hauling  rope,  but  good  rope  must  be  used  for  the 
tail  rope  if  a  return  rope  from  the  same  engine  that  does  the  hauling  is  used,  as 
the  unstranded  rope  will  not  readily  pass  through  the  pulleys.  Strands  of  i  3/8- 
in.  rope  have  also  been  tried,  but  they  were  found  to  be  too  stiff.  In  case  a  rope 
brea.ks  or  a  broken  wire  begins  to  ball  up  on  the  rope,  the  individual  wire  or 
the  ends  of  the  broken  rope  are  heated  so  as  to  take  out  the  temper,  and  then  the 
ends  are  tied  together  and  hauling  is  continued  until  the  rope  can  be  spliced 
properly. 

Gravity  Planes  at  Cheever  Mine  (By  Guy  C.  Stoltz).—  The  Cheever  Iron 
Ore  Co.,  operating  at  Port  Henry,  N.  Y.,  trams  the  concentrates,  resulting  from 
magnetic  separation,  by  gravity  planes  to  the  loading  chutes  of  the  Delaware  & 
Hudson  switch  on  the  shore  of  Lake  Champlain.  Topography  favored  the  instal- 
(ation  of  two  planes,  the  first  plane  being  700  ft.  long  with  a  drop  of  55  ft.,  and 
the  second  about  2000  ft.  long  and  a  drop  of  193  ft.  The  grade  is  not  at  all 
regular.  The  tracks  conform,  wherever  possible,  to  the  surface  of  the  ground. 
Three  3o-lb.  rails  are  laid  at  3-ft.  gage  on  each  plane  and  four  rails  with  the 
spread  for  turnouts  are  laid  at  the  half-way  points.  Side-dump  steel  cars  of 
4  i /2-ton  capacity  are  used.  A  trip  of  two  loaded  cars  is  released  on  the  slight 
down  grade  at  the  storage  bin  and  on  their  downward  journey  to  the  first  turn- 
table they  pull  the  two  empty  cars,  attached  to  the  other  end  of  the  cable,  to 
the  loading  bin.  At  the  turntable  the  loaded  cars  are  deflected  about  60°  and 


HOISTING  AND  TRANSPORTATION  187 

attached  to  the  free  end  of  the  cable  for  the  second  plane  and  on  their  downward 
course  pull  up  two  more  empties.  Sheaves  with  brakes  are  installed  at  the 
top  of  each  plane.  At  the  terminal  of  the  second  plane  the  cars  are  delivered 
to  a  turntable  and  trammed  by  hand  to  the  several  loading  chutes.  It  is 
intended  to  replace  the  first  turntable  by  a  steeply  banked  curve,  which  will 
increase  the  capacity  of  the  system  and  lower  the  surface-tramming  cost  by 
almost  one-half. 

Car  Stopping  Devices  on  Gravity  Inclines. — It  is  of  great  importance  to 
have,  at  the  upper  end  of  every  gravity  plane,  a  device  to  regulate  the  admission 
of  cars,  one  at  a  time,  to  the  plane,  and  at  the  same  time  protect  the  men  working 
at  the  bottom.  Fig.  126  illustrates  three  different  types  of  appliances  used  in 
Germany  to  accomplish  this. 

The  device  shown  in  Fig.  i  consists  of  a  pair  of  stops,  one  at  the  extreme 
top  and  the  other  a  distance  of  2  m.  down  the  incline;  both  are  raised  into 
effective  position  by  cams  keyed  to  axles  which  lie  underneath  and  across  the 
track.  The  movement  of  the  axles  is  controlled  by  levers  connected  in  such  a 
way  that  a  single  motion  of  the  hand  lever  will  raise  one  stop  into  position  and 
simultaneously  drop  the  other  out  of  position.  The  first  motion  of  the  hand 
lever  drops  the  upper  stop,  permitting  the  car  to  start  down  the  incline.  The 
car  is  blocked  by  the  second  stop,  until  a  motion  in  the  opposite  direction  lowers 
this  stop,  allowing  the  car  to  pass  down  the  incline,  and  raises  the  upper  stop 
into  position  to  retain  the  next  following  car. 

The  apparatus  shown  in  Fig.  2  consists  of  an  axle  about  i  m.  long,  lying 
below  and  parallel  to  the  rails,  and  supported  in  this  position  by  two 
journal  boxes.  To  each  end  of  the  axle  is  fastened  an  arm,  at  90°  to  one  another, 
of  such  length  that  the  extreme  end  of  each  arm  will  reach  out  and  rest  upon 
the  top  of  the  adjacent  rail,  thus  forming  an  obstruction  to  the  wheels  of  the 
cars.  When  one  rail  is  blocked,  the  other  is  free,  so  that  to  permit  the  cars  to 
pass  one  at  a  time  it  is  only  necessary  to  rotate  the  axle  through  a  few  degrees 
alternately  to  one  side  and  the  other.  The  top  tender  does  this  with  his  foot. 

The  type  of  which  two  views  are  shown  in  Figs.  3  and  4  consists  of  a  heavy, 
square  beam  pivoted  at  its  ends  and  extending  across  the  top  of  the  incline  at  a 
sufficient  height  to  permit  the  loaded  cars  to  pass  beneath  it.  At  one  end  of 
the  beam  is  a  single-notched  ratchet  engaging  a  pawl,  which  prevents  the  former 
from  rotating  beyond  a  certain  point.  Two  strong  arms  are  fastened  to  the 
square  beam  in  such  a  way  as  to  block  the  passing  of  a  car  on  either  track  so 
long  as  the  pawl  holds.  The  latter  can  be  released  by  pulling  the  handle  on  the 
end  of  the  cord,  which  is  within  reach  of  the  top  tender,  allowing  the  car  to 
pass.  As  soon  as  it  has  gone  far  enough,  the  arms  fall  back  into  their  first 
position,  and  their  impetus  carries  the  notch  in  the  ratchet  to  within  reach  of  the 
pawl,  when  the  device  is  ready  for  the  next  car.  It  is  apparent  that  the  appa- 
ratus interposes  no  obstruction  to  the  passing  of  a  car  coming  up  hill. 

The  danger  to  be  apprehended  in  the  device  last  described  is  that,  if  two 


i88 


HANDBOOK  OF  MINING  DETAILS 


HOISTING  AND  TRANSPORTATION  189 

cars  should  follow  one  another  closely,  in  passing  over  the  knuckle,  by  the  time 
the  first  car  had  gone  far  enough  to  release  the  restraining  arm,  the  second  car 
would  be  so  far  advanced  as  to  prevent  the  ratchet  from  establishing  connection 
with  the  pawl,  and  the  second  car  would  race  the  first  one  down  the  hill. 

Tail  Rope  Haulage  Operated  by  Skips. — At  the  Republic  mine,  Michigan, 
where  an  unbalanced  ore  skip  is  used,  the  descending  skip  furnishes  power  for 
hauling  empty  ore  cars.  The  tram  has  a  length  of  900  ft.,  and  has  a  sufficient 
down  grade  for  the  loaded  cars  to  run  out  by  gravity.  The  car  is  of  the  double- 
truck  type,  side  dump,  weighs  6500  Ib.  and  carries  31/2  tons  of  ore.  A  tail 
rope  is  attached  to  the  car  and  is  connected  with  a  winding  drum  on  the  axle  of 
the  sheave.  This  drum  is  8  ft.  in  diameter,  the  same  as  the  sheave.  A  friction 
clutch  is  used  to  operate  the  drum.  There  is  also  a  brake  on  the  drum  to  control 
the  speed  of  the  outgoing  cars.  Both  brake  and  friction  clutch  are  operated 
by  a  wire  rope  from  the  station  level.  An  indicator  is  also  used  to  show  the 
exact  position  of  the  car  on  the  track.  The  car  dumps  automatically.  Of  course 
in  this  particular  case  the  skip  remains  at  the  surface  until  the  car  has  reached 
the  bin  and  is  ready  for  its  return  trip.  As  the  skip  descends,  the  friction 
clutch  is  thrown  in,  and  the  empty  car  is  drawn  back  to  the  shaft  ready  to 
receive  the  ore  when  it  comes  up.  This  scheme  works  excellently  with  a 
shaft  that  is  not  working  at  its  full  capacity  or  where  the  stopping  of  the  skip 
for  a  few  moments  does  not  interfere  with  the  output.  A  second  drum  is  now 
being  installed  at  the  same  mine.  This  one  will  only  be  4  ft.  in  diameter,  as 
the  distance  for  tramming  the  ore  is  less.  In  a  system  of  counterbalanced  skip 
a  similar  scheme  is  used,  except  that  the  ascending  skip  also  brings  in  the  empty 
cars.  In  this  case  the  loaded  car  goes  out  as  the  skip  descends  and  then 
returns  as  the  skip  comes  up.  The  drum  is  at  the  station  level  and  is  operated 
by  a  rope  drive  from  the  sheave.  The  drum,  as  before,  is  provided  with  friction 
clutch  and  brake.  This  adds  a  little  extra  strain  on  the  hoisting  cable,  but 
not  enough  to  seriously  affect  its  working. 

An  Underground  Haulage  System  (By  Albert  H.  Fay). — The  problem  of 
handling  a  large  tonnage  of  ore  underground  is  usually  a  serious  one,  especially 
in  the  matter  of  cost.  The  system  that  is  now  being  installed  between  the  700 
and  800  levels  by  Witherbee,  Sherman  &  Co.,  promises  to  be  one  of  great  impor- 
tance in  handling  the  magnetite  ore  in  their  mines  at  Mineville,  N.  Y.  The 
installation  is  expensive  and  could  be  used  only  by  mines  handling  a  large 
tonnage  for  a  number  of  years.  Up  to  the  present  the  mining  has  been  carried 
on  by  working  on  large  faces  of  ore  50  to  75  ft.  high  and  several  hundred  feet 
wide.  The  ore  was  shot  down  to  the  foot  of  this  face  and  then  shoveled  by 
hand  into  the  mine  cars  which  were  pushed  to  the  shaft  by  hand.  The  ore 
is  heavy  and  in  most  cases  it  requires  at  least  three  to  five  men  to  handle  a 
single  car. 

The  scheme  now  under  way  consists  of  a  haulage  way  installed  60  ft.  below 
the  present  working  level.  This  underground  passage  is  in  the  form  of  an 


I9o  HANDBOOK  OF  MINING  DETAILS 

ellipse,  with  a  circumference  of  about  1000  ft.,  and  opens  an  orebody  500  ft. 
wide,  60  ft.  deep,  with  an  indefinite  length.  At  least  1,000,000  tons  of  ore  are 
now  blocked  out  to  be  handled  by  this  installation.  Along  this  drift  are  at 
least  a  half-dozen  raises,  inclined  at  about  45°,  which  will  be  used  as  mill  holes. 
The  mining  will  be  carried  on  by  stoping  down,  setting  the  machine  drills  near 
the  raises  and  shooting  the  ore  down  to  the  loading  platforms.  The  large 
number  of  raises  will  give  ample  space  for  a  number  of  machines  and  as  the 
work  progresses  it  will  give  still  more  room.  As  the  ore  passes  down  through  a 
raise,  it  falls  upon  a  loading  platform  built  of  concrete.  This  platform  is  4  1/2 
ft.  high,  10  or  12  ft.  long,  8  or  10  ft.  wide  according  to  the  condition  of  the  ground, 
with  a  loading  chute  3  ft.  above  the  top  of  rail.  It  is  built  with  a  slope  from  the 
back  to  the  front  as  well  as  a  slope  from  each  end  to  the  center.  The  chute 
will  be  covered  with  sheet  iron. 

At  the  shaft  an  8oo-ton  storage  bin  has  been  built,  the  bottom  of  which  is 
46.5  ft.  below  the  top  of  the  car  tracks.  The  tipple  is  26  ft.  long  and  will  dump 
three  cars  at  once.  It  is  operated  by  an  electric  motor  and  revolves  upon 
trunnions.  The  bin  gate  and  the  loading  chute  are  operated  by  air  hoists. 
An  auxiliary  tipple  at  the  left  will  dump  only  one  car  at  a  time  and  is  to  be  used 
only  when  tramming  by  hand  in  case  the  electric  motor  haulage  system  is  out 
of  commission.  This  is  also  to  be  used  as  a  waste  pocket  when  it  is  necessary  to 
dispose  of  waste  from  the  same  loading  station.  Between  the  shaft  and  the 
bin  is  a  rock  pentice  which  serves  as  a  support  for  the  auxiliary  tipple  and  at  the 
same  time  forms  the  front  wall  of  the  ore  pocket. 

The  cars  are  of  three  tons'  capacity  and  will  be  handled  in  trains  of  nine 
cars  each.  The  motor  truck  has  two  25-h.p.  motors  operated  on  2  20- volt  direct 
current.  The  haulage  track  is  45-lb.  rails.  While  lighter  rails  could  be  used, 
practice  has  demonstrated  that  the  heavy  rails  are  better  as  they  are  not  easily 
broken  by  heavy  pieces  of  ore  falling  upon  them.  They  are  also  more  solid, 
require  less  ties  and  give  a  better  track.  The  motor  in  passing  around  the  track 
gathers  up  the  loaded  cars  and  pushes  them  in  front.  When  the  tipple  is  reached, 
three  cars  are  dumped.  These  are  then  pushed  through  the  tipple  and  three 
more  dumped  until  all  are  empty.  The  motor  then  goes  around  the  tipple  on  a 
side  track  and  couples  the  nine  empty  cars  on  behind.  When  the  first  loading 
station  is  reached,  the  loaded  cars  are  picked  up,  and  one,  two  or  three  empty 
cars  left  in  their  place  as  may  be  desired.  In  this  way  the  motor  will  be  in 
operation  all  the  time  and  with  an  8oo-ton  storage  bin  it  will  be  possible  to  keep 
the  hoist  working  up  to  its  full  capacity  without  the  loss  of  time  which  was  usual 
when  the  cars  were  operated  by  hand  power.  When  this  equipment  is  completed, 
it  is  expected  to  be  able  to  handle  1000  tons  per  lo-hour  shift.  The  ore  is 
hoisted  in  self-dumping  skips.  I  am  indebted  to  S.  LeFevre,  chief  engineer, 
Witherbee,  Sherman  &  Co.,  for  the  above  information. 

An  Underground  Hoisting  Station  (By  S.  A.  Worcester). — Fig.  127  shows 
the  layout  of  a  winze  hoisting  station  in  a  mine  in  southwestern  Colorado. 


HOISTING  AND  TRANSPORTATION 


191 


The  winze  is  nearly  square  in  section  and  is  divided  into  three  compartments. 
The  largest  compartment  is  rectangular  in  section  and  is  used  for  hoisting  ore 
in  cars  of  22oo-lb.  capacity,  two  cars  being  placed  tandem  on  the  single  deck 
of  the  cage.  The  i5o-h.p.  electric,  two-reel  cage  hoist  occupies  a  large  room 
excavated  in  hard  rock  at  the  west  side  of  the  station;  it  is  not  shown  in  the 
illustration.  The  flat  rope  from  one  of  the  reels  runs  over  the  large  upper 
sheave  at  the  left,  thence  down  to  the  cage.  The  flat  rope  on  the  other  reel 
runs  over  the  lower  sheave  supported  on  an  A-frame  thence  down  the  shaft 
to  an  overbalance  weight.  This  weight  is  made  of  several  sections  and  is 
similar  to  the  ordinary  elevator  weight.  It  is  so  weighted  that  the  work  of  the 
motor  when  raising  the  weight  is  the  same  as  when  raising  the  cage  with 
its  maximum  load. 


FIG.    127. — WINZE  HOIST  STATION  IN  A  COLORADO   MINE. 

The  two  other  compartments  are  nearly  square  in  section.  One  is  used  as 
a  pipe  and  ladder  compartment,  the  other  is  lined  with  planks  throughout 
and  is  used  only  as  a  bucket  hoistway  for  sinking  operations.  This  bucket  is 
raised  by  the  75-h.p.  electric  motor  shown  in  the  upper  room  on  the  right- 
hand  side  of  the  illustration.  When  the  bucket  has  been  raised  above  the  level 
of  the  floor  of  this  room  the  counterbalanced  door  is  lowered  and  the  dumping 
rope  shown  at  the  left  of  the  bottom  of  the  bucket  is  hooked  into  the  ring  at 
the  bottom  of  the  bucket.  Upon  lowering,  the  bucket  turns  over  and  dumps 
its  load  into  the  bin  below  from  which  the  ore  or  rock  is  drawn  into  cars  and 
hauled  2400  ft.  along  the  vein  then  2200  ft.  through  an  adit  to  daylight;  thence 


192  HANDBOOK  OF  MINING  DETAILS 

it  is  conveyed  11,500  ft.  by  a  Blei chert  tramway  to  the  mill.  The  operating 
levers  of  the  hoist  are  placed  near  the  winze  so  that  the  hoist  engineer  can 
attend  to  the  dumping. 

At  the  left  of  the  illustration  a  third  room  is  shown,  excavated  in  rock,  in 
which  is  shown  a  5o-h.p.  two-drum  hoist.  Above  this  room  the  position  of 
an  inclined  raise  is  shown.  The  hoist  rope  passes  up  the  raise  for  500  ft., 
over  a  sheave,  thence  down  to  the  cage.  The  y/8-in.  rope  on  the  drum  passes 
over  a  sheave  at  the  collar  of  the  winze,  thence  down  the  cage  compartment  to  an 
overbalance  weight  that  runs  by  the  side  of  and  is  similar  to  the  weight  used 
on  the  cage  hoist.  The  raise  hoist  is  used  for  raising  men,  timbers  and 
supplies  to  the  upper  levels.  Direct  current  for  all  these  hoists,  for  other 
hoists  in  the  mine  and  for  the  mine  locomotives  is  supplied  from  a  storage- 
battery  plant  at  the  surface.  The  battery  is  charged  by  rotary  converters 
and  a  booster,  the  current  being  generated  at  a  hydro-electric  power  plant 
several  miles  from  the  mine. 

Catenary  Hoisting  Cable. — There  is  an  unusual  installation  of  a  hoisting 
cable  at  the  Republic  mine,  Republic,  Mich.  In  order  to  utilize  a  central 
power  plant,  it  became  necessary  to  have  a  cable  operate  across  a  small  lake 
a  distance  of  1800  ft.  before  the  headframe  of  the  shaft  could  be  reached.  The 
shaft  is  about  800  ft.  deep  and  is  inclined  at  an  angle  of  70°.  In  constructing 
the  cable  across  the  lake,  the  towers  for  supporting  the  cable  would  be  very 
high  if  an  attempt  had  been  made  to  keep  the  cable  in  a  straight  line  from  the 
drum  to  the  shaft.  A  catenary  curve  between  the  two  places  was  figured  out 
on  the  basis  of  the  breaking  load  of  the  cable.  Towers  were  erected  at  intervals 
of  100  ft.  entirely  across  the  lake,  the  one  near  the  center  being  only  10  or  12  ft. 
above  the  level  of  the  lake.  The  catenary  is  so  flat  that  the  cable  has  no  tend- 
ency to  lift  off  the  pulleys  and  at  the  same  time  the  friction  on  the  pulleys  is 
less  than  it  would  be  if  the  cable  were  worked  in  a  straight  line.  A  large  saving 
also  resulted  from  the  construction  of  smaller  towers. 

Double  Hoisting  Cables. — At  the  Beust  shaft  of  the  Deutschland  mine  at 
Hasslinghausen,  Germany,  the  slipping  of  the  cable  is  prevented  by  using  a 
double  rope  running  on  double-grooved  sheaves.  Thus  the  bearing  area  on 
the  packing  in  the  sheaves  is  increased.  The  cables  are  attached  to  the  cage 
by  a  drawbar  to  which  the  cables  are  fastened  by  turnbuckles.  These  turn- 
buckles  permit  the  strain  on  the  cables  to  be  equalized.  Bolts  prevent  the 
moving  of  the  turnbuckles  by  the  twisting  of  the  ropes. 

Hoisting  Cable  Run  through  a  Drill  Hole. — A  6-in.  drill  hole  from  the 
surface  penetrated  a  body  of  ore  which  later  was  stoped  out.  Upon  sinking 
the  drill  hole  ore  was  struck  at  a  lower  level  and  a  winze  sunk  with  the  drill  hole 
as  a  center.  In  order  to  work  the  winze  to  any  depth  it  would  have  been  neces- 
sary to  install  a  hoist  underground,  which  was  not  practical.  A  hoist  was  there- 
fore erected  at  the  surface  and  the  cable  operated  through  the  drill  hole.  Ore 
was  hoisted  to  the  main  working  level  and  then  trammed  to  the  hoisting  shaft. 


HOISTING  AND  TRANSPORTATION  193 

Rapid  Hoisting  with  Wire  Guide  (By  Hugh  C.  Watson). — A  remarkable 
feat  of  hoisting  is  the  one  now  in  operation  at  La  Ojuela  mine  in  the  State 
of  Durango,  Mexico.  By  means  of  wire  guides  and  an  unbalanced,  first- 
motion  hoist,  a  bucket  holding  about  1800  Ib.  of  ore  is  filled,  hoisted,  dumped 
and  returned  to  the  bottom  of  a  lyoo-ft.  shaft  in  2  minutes  10  seconds.  This 
is  not  record  time,  but  ordinary  hoisting  speed.  It  has  been  done  in  2  minutes 
flat. 

Wire-rope  guides  are  not  the  best  that  can  be  used,  but  they  have  certain 
advantages,  especially  when  working  a  mine  on  a  prospecting  basis,  where 
first  cost  is  one  of  the  essential  features.  The  principal  advantages  are  small 
cost,  ease  and  speed  with  which  they  can  be  installed  and  shifted,  that  they 
will  work  in  any  sort  of  a  vertical  shaft,  and,  considering  the  speed  attained  at 
Ojuela,  they  do  not  seriously  limit  the  capacity  of  the  haulage  system. 

Six  men  are  employed  in  connection  with  the  hoisting  plant:  One  is  the 
hoist  man,  two  are  topmen  and  three  are  fillers.  The  topmen  do  nothing 
but  close  the  doors,  dump  the  bucket  and  open  the  doors  for  the  down  trip. 
Of  the  three  men  at  the  bottom  of  the  shaft,  one  sits  above  the  ore-bin  door 
with  a  bar  to  see  that  the  door  does  not  get  stopped  up.  One  stands  directly 
in  the  shaft  to  hook  and  unhook  the  buckets  as  they  are  pushed  to  him  by  the 
third  man.  The  empty  bucket  is  caught  on  a  low  truck  set  to  receive  it  between 
the  guides.  The  man  in  the  shaft  unhooks  it  from  the  crosshead,  the  third 
man  gives  his  full  bucket  a  push  that  shoves  the  empty  bucket  and  its  truck 
to  the  far  side  of  the  shaft,  the  shaft  man  then  hooks  the  full  bucket  to  the 
crosshead  and  gives  the  signal  to  hoist.  The  bucket  now  at  the  bottom  is 
filled  while  the  other  bucket  is  being  hoisted  and  dumped. 

The  bucket  itself  is  of  the  ordinary  type  attached  to  the  bail  slightly  below 
center,  and  kept  upright  by  means  of  a  link  and  ear.  The  doors  on  the  shaft 
are  of  the  type  known  locally  as  "doghouse."  They  are  simply  two  doors 
which,  when  closed,  form  a  gable  over  the  mouth  of  the  shaft  on  which  the  ore 
slides  into  a  bin  on  either  side.  The  guides  are  5/8-in.  four-strand,  galvanized- 
steel,  wire  rope.  They  are  attached  at  the  bottom  to  a  cable  that  is  stretched 
across  the  shaft  below  the  track  level.  This  cross  cable  is  anchored  on  each 
side  of  the  shaft  to  a  i  i/2X  i8-in.  eye-bolt,  which  has  a  split  point  and  wedge 
to  keep  it  fixed  solidly. 

On  top,  these  guides  pass  over  two  small  sheaves  and  down  to  a  drum  that 
serves  to  hold  an  excess  of  rope  and  is  also  fitted  with  a  counterweight,  a  crank 
handle  and  dog,  so  that  the  guides  can  be  easily  and  rapidly  tightened.  This  is 
only  one  of  the  many  ways  that  these  guides  can  be  fastened;  in  fact,  on  this 
same  mine  there  are  at  the  present  time  seven  shafts  that  have  wire  guides,  and 
each  one  has  its  own  system,  each  taking  advantage  of  some  peculiar  condition 
existing  in  that  shaft. 

The  crosshead  is  made  in  the  shape  of  a  triangle,  of  6X6-in.  pine,  and  at 
the  lower  side  two  lead  guide  blocks  are  used  of  such  a  form  as  to  be  easily 
13 


J94  HANDBOOK  OF  MINING  DETAILS 

changed  and  solidly  attached  to  the  triangle.  The  guides  last  indefinitely,  but 
the  guide  blocks  have  to  be  constantly  replaced.  On  shaft  No.  4,  which  hoists 
about  200  tons  daily,  the  guide  blocks  last  four  days.  When  lowering  men, 
four  accommodate  themselves  on  the  triangle,  four  stand  on  the  edge  of  the 
bucket  and  two,  sometimes  three,  climb  into  the  bucket.  The  principal  disad- 
vantage of  this  method  of  hoisting  is  that  it  offers  absolutely  no  way  of  attaching 
safety  devices,  and  that  it  takes  a  larger  shaft  for  the  same  size  of  bucket.  The 
principal  advantages,  other  than  those  already  mentioned,  are  that  no  timber  is 
required  in  the  shaft,  the  system  can  be  used  either  with  the  balanced  or  un- 
balanced method  of  hoisting,  and  that  by  this  method  a  bucket  can  be  passed 
through  a  cave  or  a  big  stope,  where  it  would  be  costly  to  put  timbers.  This 
last  is  the  principal  reason  for  its  adoption  at  Ojuela. 

Concrete  Chute  Bridging  a  Level. — Concentrating  hoisting  at  a  few  levels 
is  a  practice  that  is  growing  in  favor  at  many  large  mines.  At  the  Osceola, 
No.  13  shaft  of  the  Calumet  &  Hecla  company,  the  ore  from  five  levels,  each 
100  ft.  apart,  is  delivered  at  the  level  through  a  chute  in  the  shaft  pillar.  This 
chute  is  inclined  at  an  angle  of  40°  from  the  horizontal.  The  ore  is  drawn  from 
it  into  a  car  of  7  1/2  tons  capacity,  the  flow  of  ore  being  controlled  by  a  chute 
gate  of  the  hinged  type.  As  this  chute  was  cut  after  the  levels  were  driven,  it 
was  necessary  to  continue  it  from  the  opening  in  the  roof  of  the  drift  diagonally 
across  to  the  similar  opening  in  the  floor,  near  the  opposite  wall.  This  was 
done  by  bridging  the  gap  with  a  long,  reinforced-concrete  box  without  ends. 
The  bottom  of  the  box  was  made  24  in.  thick,  and  was  reinforced  with  old  30- 
and  4o-lb.  rails.  Large  blocks  of  rock  from  the  vein  walls,  some  of  which  were 
1 6  to  1 8  in.  diameter,  were  imbedded  in  the  concrete  in  making  the  bottom, 
as  it  was  believed  that  this  material  would  withstand  abrasion  by  the  ore  better 
than  concrete  alone;  a  1:2:5  concrete  mixture  was  used.  The  sides  of  the 
box  were  made  12  in.  thick  at  the  floor  and  tapered  to  a  thickness  of  6  in. 
at  the  roof.  The  cover  or  top  of  the  box  was  made  of  concrete  12  in.  thick, 
and  it,  as  well  as  the  sides,  was  reinforced  with  old  rails.  An  opening  in  one 
side  of  the  box  at  the  floor  on  each  level  afforded  means  of  dumping  ore  into 
the  chute.  A  grizzly  was  placed  over  the  opening,  and  was  held  in  place  by 
a  12  X  i2-in.  timber,  to  which  the  grizzly  bars  were  screwed. 

A  Cheap  Mine  Road  (By  S.  H.  Brockunier).— Recently  I  had  occasion  to 
build  2600  ft.  of  a  side-hill  road  to  the  Erie  mine,  Gaston,  Calif.  I  had  only  a 
week  to  complete  the  road  and  the  problem  was  further  complicated  by  fallen 
trees  3  or  4  ft.  in  diameter,  and  several  hundred  feet  of  swampy  ground,  so  I 
decided  to  place  main  reliance  on  dynamite.  The  first  day  only  two  pairs  of 
men  were  put  to  work,  one  pair  at  each  end  of  the  road,  in  order  to  see  how 
much  they  would  accomplish  and  how  many  men  would  be  needed.  In  this 
way  I  estimated  that  eight  men  would  complete  the  road  in  seven  days;  as 
a  matter  of  fact  the  ditching  of  the  swamp  detained  them  a  day  longer  and 
eight  days  were  actually  consumed  in  the  construction.  The  men  were  given 


HOISTING  AND  TRANSPORTATION 


I9S 


40%  dynamite,  fuse,  caps,  augers,  and  bars.  They  were  told  to  put  5-ft. 
vertical  holes  along  the  upper  side  of  the  proposed  road  and  loosen  the  earth 
with  dynamite,  regulating  their  charges  so  as  to  move  the  earth  as  much  as 
possible  toward  the  downhill  or  lower  side.  In  this  way  not  a  pick  was  used 
on  the  entire  road  and  shoveling  was  reduced  to  a  minimum.  When  a  fallen 
tree  was  encountered  it  was  bored  for  a  charge  of  dynamite,  blasted  in  two,  and 
pushed  out  of  the  way.  The  swamp  was  corduroyed  with  8-ft.  slabs  blasted 
from  fallen  trees.  These  slabs  or  poles  should  have  been  12  ft.  long,  because 
if  shorter  they  rock  too  much  in  soft  mud.  Cutting  and  splitting  trees  with 
dynamite  is  an  easy  method  when  compared  with  axe,  saw,  hammer  and  wedges 
and  the  necessary  men  to  handle  such  tools.  The  total  cost  of  this  road  was, 
seven  boxes  of  dynamite,  $49 ;  fuse  and  caps,  $13 ;  labor,  $202 ;  total,  $264.  This 
is  at  the  rate  of  10  cents  per  lineal  foot  for  an  8-ft.  road.  The  day  the  road  was 
completed  a  6ooo-lb.  load  was  drawn  over  it  with  ease  and  it  has  been  teamed 
over  steadily  ever  since. 

HOISTS 

Snatch  Blocks  Applied  to  Hoisting  (By  Stephen  L.  Goodale).— At  the 
Bristol  mines,  at  Pioche,  Lincoln  county,  Nev.,  a  large  amount  of  rich  ore  was 


FIG.    128. — SNATCH  BLOCK  APPLIED   TO   MINE  HOISTING. 

taken  out  from  an  oreshoot  or  chimney  close  to  the  Gipsy  shaft,  and  as  the 
work  got  away  from  the  shaft  a  small  electric  hoist  was  installed.  This  was 
found  to  be  an  expensive  arrangement,  especially  as  the  electric  drill,  on 
account  of  which  the  dynamo  was  primarily  installed,  proved  unsatisfactory,  and 
the  dynamo  had  to  be  driven  for  this  hoist  alone.  This  meant  an  extra  man 
at  $4  per  day  to  drive  the  dynamo,  also  the  hoisting  engineer  below  and  the 
hoisting  engineer  at  the  top  of  the  Gypsy  shaft,  each  of  whom  got  $4  per  day. 


196 


HANDBOOK  OF  MINING  DETAILS 


To  replace  this,  two  i2-in.  snatch  blocks  were  placed  at  the  45o-ft.  station — 
one  in  the  floor  of  station  at  A,  as  shown  in  Fig.  128,  close  to  the  shaft,  and  one 
at  B  hung  from  a  well  braced  stull  in  line  with  the  winze.  The  bucket  was 
hoisted  from  the  winze  and  lowered  to  a  truck  on  the  station  level.  The  hoist 
rope  was  run  out  to  get  slack  and  taken  off  the  snatch  blocks;  the  slack  was  again 
taken  up  and  the  truck  run  to  the  shaft.  The  snatch  blocks  were  placed,  as 
shown  in  the  diagram,  to  allow  the  main  hoisting  rope  being  carried  around  the 
snatch  blocks  and  down  the  winze.  This  arrangement  could  be  worked  rapidly 
and  lessened  the  number  of  men,  cutting  out  the  high-priced  engineer  at  the 
May  Day  shaft  and  replacing  the  $4  man  at  the  450  level  with  a  $3  man,  whose 
duty  it  was  to  manage  the  hoisting  from  the  winze  and  the  placing  of  the 
hoisting  rope  around  the  snatch  blocks.  Frequently  also  during  a  shift 
this  man  was  able  to  get  out  several  hundred  pounds  of  high-grade  ore  near  the 
shaft.  It  might  seem  that  there  would  be  danger  of  overwinding  and  pulling 
out  a  snatch  block,  considering  that  the  bucket  had  to  be  stopped  within  8  in. 
of  a  given  point  on  the  450  level,  and  that  the  hoisting  engineer  had  to 
rely  largely  on  a  bell  signal.  Again,  it  was  difficult  to  maintain  a  mark  on  the 
rope  for  the  engineer's  guidance.  However,  no  trouble  was  experienced. 
While  this  cannot  be  considered  an  ideal  arrangement  for  mining  a  large  deposit, 
still  it  worked  satisfactorily  for  prospecting  more  than  100  ft.  below  the  level  of 
the  snatch-block  station. 

A  Simple  Form  of  Lift.— A  coal  lift  used  at  some  of  the  steam  plants  on  the 
Mesabi  range  is  shown  in  Fig.  129.     The  coal  is  dumped  on  the  ground  outside 


.Pulley 


2  Groove  Pulley 


3  Groove  Pulley 


FIG.    129. — SKETCH   SHOWING    PISTON  ARRANGEMENT    FOR   COAL   LIFT. 

the  boiler  house.  It  is  then  loaded  by  hand  into  i-ton  cars  and  trammed  to 
this  lift  and  elevated  to  the  bunkers.  In  most  of  the  newer  plants,  where  it  is 
possible,  the  coal  is  discharged  directly  from  the  railroad  cars  to  the  bunkers, 
thus  saving  the  extra  handling  with  the  lift.  The  device  is  operated  by  a  steam 
cylinder  about  10  ft.  long  by  12  or  14  in.  in  diameter.  At  the  end  of  the  piston 
rod  is  a  double-grooved  sheave  over  which  two  3/4-in.  cables  operate.  One 
end  of  these  cables  is  fastened  at  A ,  so  that  in  this  way  when  the  piston  moves 
10  ft.  it  will  lift  the  car  20  ft.  The  car  platform  works  between  guides  and  is 
balanced  by  a  counter-weight  B.  Steam  is  turned  on  at  C,  the  exhaust  D  being 


HOISTING  AND  TRANSPORTATION  197 

open,  forcing  the  piston  along  and  lifting  the  car  of  coal.  To  lower  the  car, 
shut  off  the  steam  and  open  the  exhaust  valve  E  and  the  weight  of  the  car  will 
operate  the  device  by  gravity.  The  area  of  the  piston  must  be  such  that  the 
product  of  the  area,  steam  pressure  and  distance  shall  be  in  excess  of  the  load, 
multiplied  by  its  distance.  If  these  are  equal  it  gives  a  balanced  system  and 
no  movement  takes  place.  The  amount  of  steam  consumed  is  small,  simply 
enough  to  fill  the  cylinder.  The  steam  and  exhaust  valves  may  be  at  any 
convenient  place,  not  necessarily  as  shown  in  the  diagram. 

Cable  Drum  for  Lowering  Timber. — One  of  the  best  cable  drums  for 
letting  mine  timber  and  lagging  down  a  shaft  is  shown  in  Fig.   130.     This 


I        Shaft 
FIG.    130. — DEVICE   FOR  LOWERING   TIMBERS    IN   IRON  MINES. 

form  is  in  use  by  most  of  the  underground  mines  of  northern  Minnesota. 
The  timber  or  lagging  is  loaded  on  a  small  car  and  pushed  to  the  edge  of  the 
shaft.  A  double  slip  noose  is  placed  around  the  timber  and  the  rear  end  of 
the  car  raised  up  so  the  load  drops  into  the  shaft.  It  is  allowed  to  drop  slowly 
down  the  shaft  by  the  friction  band  E,  controlled  by  the  lever  L.  As  the  rope  A 
is  unwinding,  the  rope  B  is  being  wound  up  and  is  kept  to  the  side  of  the  shaft 
by  a  guide  on  the  collar  of  the  shaft.  The  end  of  rope  B  reaches  the  collar  as 
the  load  strikes  bottom;  and  another  load  is  then  attached  to  rope  B,  which 
again  pulls  up  the  unloaded  rope  with  chain.  The  drum  is  of  sufficient  length 
to  allow  for  any  reasonable  length  of  rope.  The  larger  the  load  handled 
more  turns  of  rope  are  necessary  to  hold  it.  A  3/8-in.  wire  rope  is  used  in 
most  cases  and  will  wear  for  years.  The  friction  band  E  is  made  of  strap 
iron  4  in.  wide  and  1/4  in.  thick.  The  shafts  are  lined  with  plank  placed 


198 


HANDBOOK  OF  MINING  DETAILS 


vertically,  so  that  the  bundle  of  moving  timbers  does  not  catch  in  the  shaft 
timbering. 

A  Portable  Winch. — A  portable  winch  is  an  extremely  useful  piece  of 
machinery  at  any  mining  operation.  At  the  Republic  mine,  Republic,  Mich., 
an  ordinary  hand  winch  is  mounted  upon  a  heavy  frame  which  in  turn  is 
mounted  upon  trucks  for  a  standard-gage  track.  A  7  i/2-h.p.  electric 
motor  is  also  mounted  on  the  same  frame  and  connected  by  belt  to  the  pinion 
shaft  which  operates  the  drum.  A  friction  clutch  is  used  to  throw  the  drum 
in  gear.  This  winch  can  be  moved  to  any  point  where  there  is  a  car  track  and 
is  easily  anchored  by  fastening  to  the  rails,  or  by  means  of  chains  to  stakes 
in  the  ground.  Where  electric  power  is  available,  this  arrangement  is  quite 
satisfactory,  as  power  can  be  obtained  from  any  point  along  the  line.  The 
entire  apparatus  is  not  so  heavy  but  that  it  can  be  moved  over  smooth  ground 
without  the  aid  of  rails.  This  one  is  used  where  a  temporary  hoist  is  required, 
and  also  in  the  erection  of  trestles  for  car  tracks  on  stock  piles. 

Combination  Timber  Hoist  and  Winch. — The  design  of  a  combination 
drum  for  lowering  mine  timbers  and  a  winch  for  hoisting  is  shown  in  Fig. 


Coimterweight- 


FIG.    131. — TIMBER  HOIST  AT  HEMATITE   MINE,    ISHPEMING,    MICH. 

131.  The  apparatus  here  described  is  used  at  the  Hematite  mine,  Ishpeming, 
Mich.  The  drum  is  18  in.  in  diameter,  3  ft.  long  and  is  mounted  upon  a 
heavy  frame  of  8X  8-in.  timbers  as  shown.  On  one  end  of  the  drum  is  a  brake 
wheel  and  band,  also  a  cog  wheel  into  which  a  small  pinion  meshes.  This 
pinion  may  be  thrown  out  by  means  of  a  lever  A ,  and  the  timbers  lowered  by 
the  use  of  the  band  brake  only.  The  drum  is  divided  into  two  sections,  upon 


HOISTING  AND  TRANSPORTATION 


199 


which  are  placed  two  cables.  As  one  cable  is  run  out  with  the  lowering  of  the 
timber,  the  other  cable  is  being  wound  up  ready  to  receive  a  second  load  of 
timbers.  In  the  event  any  of  the  timbers  are  too  heavy  for  the  brake  to  control 
their  descent,  the  pinion  may  be  thrown  in  and  the  crank  employed.  The 
winch  may  be  used  in  hoisting  pieces  of  machinery. 

Interchangeable  Arrangement  for  Steam  and  Electric  Hoist.— At  the 
Gold  Cliff  mine  of  the  Utica  company  at  Angels  Camp,  Calif.,  the  hoisting 
engine  is  simply  arranged  for  the  use  of  either  electric  or  steam  power.  The 
hoist  was  originally  built  for  steam  power,  but  it  is  more  economical  now  to 
use  electricity  as  a  motive  power,  so  it  has  been  rigged  for  direct  connection 


FIG.    132. — INTERCHANGEABLE   ARRANGEMENT   FOR   STEAM    OR   ELECTRIC  HOIST. 

to  a  motor.  When  electric  power  is  to  be  used  for  driving  the  engine,  the 
connecting  rods  to  the  steam  cylinders  are  taken  off  and  a  specially  constructed 
rim  with  ratchet  gearing  fastened  to  the  crank,  the  rim  engaging  the  pinioned 
drive  pulley  on  the  motor.  The  crank  on  the  engine  is  a  solid  wheel.  A  wheel 
of  larger  diameter,  the  size  desired  to  secure  the  proper  hoisting  speed,  is 
turned  down  so  as  to  fit  flush  against  and  partially  over  the  crank,  the  projecting 
edge  forming  a  rim  or  tire  about  the  latter.  Both  the  crank  and  the  auxiliary 
wheel  are  drilled  for  tapered  bolts  by  which  they  are  fastened  securely  to  each 
other.  Fig.  132  illustrates  the  details  of  construction.  The  rim  can  be 
slipped  over  the  crank  and  bolted  to  it  in  a  few  minutes;  then,  by  disengaging 
the  connecting  rods  on  the  engine,  the  hoist  is  ready  for  electric  driving.  A 
rawhide  pinion  is  used  to  reduce  noise  and  friction.  This  arrangement  permits 
a  satisfactory  interchangeable  driving  of  the  hoist  without  making  any  serious 
alteration  of  the  plant. 

A  Cone  Friction  for  Mine  Hoists. — Friction  hoists  are  used  at  mines 
because  they  are  usually  the  simplest  and  cheapest  hoists  that  can  be  built. 
When  two  drums  are  mounted  on  one  shaft  for  hoisting  in  balance,  it  is  often 
desirable  to  work  one  drum  while  the  other  is  at  rest  and  one  of  the  methods 
of  transmitting  motion  from  the  engine  to  these  drums  is  by  means  of  a  friction 


200  HANDBOOK  OF  MINING  DETAILS 

gear.  The  friction  hoist  finds  its  widest  application  in  mining  where  heavy 
loads  are  raised  while  the  engine  is  using  steam  and  light  loads  are  lowered  at 
a  speed  controlled  solely  by  the  brake  and  friction  gear,  no  steam  being  used  in 
the  engine.  Most  friction  hoists  are  not  built  with  reversing  engines  unless 
occasional  heavy  loads  are  to  be  lowered.  Hoisting  through  winzes  where 
rapid  return  of  the  empty  bucket  is  a  requirement  is  a  typical  use  of  the  friction 
hoist. 

There  are  two  types  of  friction  gear  more  widely  used  than  others  for  driving 
hoisting  engines,  the  band  and  cone  frictions.  The  band  friction  consists  of 
two  semi-circular  bands  of  wrought  iron  that  carry  wooden  shoes  and  which 
can  be  tightened  to  grasp  the  drum  in  a  manner  exactly  similar  to  the  operation 
of  a  band  brake.  The  cone  friction  consists  of  a  ring,  in  snape  like  the  frustrum 
of  a  hollow  cone,  which  is  bolted  to  the  part  of  the  hoist  actuated  by  the  engine 
through  gears.  This  cone  engages  a  similar  larger  cone  bolted  to  the  drum. 
Where  one  such  ring  is  used  on  the  drum  the  gear  is  termed  single  cone  friction; 
if  there  are  two  rings,  one  of  which  engages  the  outside  and  one  the  inside  of 
the  engine  cone,  the  gear  is  called  a  double  cone  friction.  The  engine  cone 
is  therefore  male  and  the  drum  cone  female.  Contact  is  made  and  broken  by 
shifting  the  drum  laterally  upon  its  shaft.  Such  lateral  movement  of  the 
drum  varies  from  1/32  to  1/8  in.  and  is  effected  through  a  hand  lever  operating 
shifting  devices  that  vary  in  construction  in  hoists  of  different  manufacture. 

In  the  earlier  forms  of  friction  gear  two  metal  surfaces  were  employed  but 
when  any  slip  occurred  the  amount  of  heat  developed  was  excessive.  This 
form  was  succeeded  by  that  in  which  one  member  was  made  of  wood  and  the 
other  of  iron  or  steel.  In  the  double  cone  hoists  the  male  cone  is  made  of 
wood  and  the  female  cones  of  iron  as  it  is  easier  to  replace  the  male  cone 
when  worn  out;  the  wooden  cone  of  course  wears  more  rapidly  than  the  metal. 
Some  manufacturers  make  the  wooden  cones  so  that  the  friction  surface  is 
against  the  grain  of  the  wood  as  such  a  surface  wears  longer;  the  surface 
parallel  to  the  grain  gives  a  better  hold  and  as  replacement  of  the  cone  is  easy 
some  manufacturers  prefer  to  use  this  surface  and  change  cones  more  frequently. 

Single  cones  can  be  adjusted  as  they  wear  but  this  is  compensated  in  part  by 
the  greater  amount  of  wear  they  are  subjected  to  over  double  cones.  The 
object  of  making  the  gears  in  the  form  of  a  truncated  hollow  cone  is  to  get 
sufficient  surface  of  contact  and  reduce  the  amount  of  end  thrust.  The  best 
angle,  for  the  face  of  these  cones,  as  determined  by  experiments,  is  30°;  that  angle 
is  best  for  quick  release  and  brings  the  least  pressure  against  the  mechanism 
for  shifting  the  drum  on  its  shaft. 

An  improvement  in  wooden  cones  is  shown  in  Fig.  133.  The  two  surfaces 
of  the  wooden  male  cone  that  engage  the  iron  surfaces  of  the  female  cones  are 
bored,  staggered  as  shown.  Into  the  holes  cork  cylinders,  a  little  larger  in 
diameter  than  the  holes,  are  forced  under  pressure  so  that  they  bulge  above 
the  level  of  the  wooden  surface.  The  convex  surfaces  of  the  cork  insets  are 


HOISTING  AND  TRANSPORTATION  20 1 

then  planed  flat  but  allowed  to  project  about  1/32  in.  above  the  wooden 
surface  of  the  cone.  A  peculiar  fact  noted  in  the  use  of  these  insets  is  that 
while  both  wood  and  cork  surfaces  eventually  wear  the  corks  always  protrude 
about  the  same  amount  until  the  cone  is  worn  out — due,  no  doubt,  to  the 
squeeze  to  which  the  cork  is  subjected  by  being  forced  under  pressure  into  a 
comparatively  small  hole. 

In  the  cone  with  cork  insets,  the  holding  power  on  the  drum  is  increased 
about  100%.  This  means  that  the  hoisting  engineer  has  only  to  exert  about 
one-half  the  pressure  on  the  lever  to  hoist  the  load.  The  cone  withstands 
the  effects  of  heat  better  than  the  plain  wooden  cone,  in  fact  the  cork  will  not 
burn  so  readily  as  the  wood  and  as  the  drum  does  not  slip  as  much  as  with  wood, 
the  cone  is  more  durable.  Oil  and  water  do  not  cause  slipping  to  anything 
like  the  extent  that  they  do  with  a  plain  wooden  surface.  The  cone  also  takes 
hold  and  lets  go  more  quickly. 


FIG.    133. — A  HOIST  FRICTION  WITH  CORK  INSETS. 

The  efficiency  of  a  friction  cone  has  nothing  to  do  with  the  elasticity  of  the 
materials,  but  with  the  character  of  the  surfaces  in  contact.  The  good  results 
obtained  by  the  use  of  cork  insets  seem  to  indicate  that  a  yielding  surface  is  an 
advantage,  but  in  the  light  of  more  recently  developed  friction  devices  this  is 
not  proven  to  be  the  case  in  all  instances. 

Deep  Sinking  with  Gasoline  Hoists. — At  the  Boston  &  Ely  property 
at  Kimberley,  Nev.,  prospecting  has  been  done  by  sinking  shafts  far  beyond 
what  is  generally  thought  to  be  the  range  of  gasoline  hoists.  Of  course/  it 
probably  would  have  been  more  economical  to  use  larger  hoists  driven  by 
electricity,  but  the  work  shows  what  can  be  accomplished  with  gasoline  engines 
by  those  who  understand  them.  By  means  of  a  i5-h.p.  Fairbanks- Morse 
gasoline  hoist  having  a  rope  speed  of  200  ft.  per  minute,  the  shaft,  which  was 
timbered  with  4X4-in.  sets,  was  sunk  to  a  depth  of  840  ft.,  using  a  bucket  and 
crosshead  that  gave,  with  the  weight  of  the  rope,  a  dead  load  of  one  ton.  This 
840  ft.  was  the  limit  of  the  rope  and  so,  when  a  new  rope  was  ordered,  a  40- 


202  HANDBOOK  OF  MINING  DETAILS 

h.p.  gasoline  hoist  of  the  same  make  was  installed,  but  with  the  old  hoist  a  speed 
of  50  ft.  per  month  was  attained  in  sinking.  With  the  4o-h.p.  hoist  the  shaft 
was  sunk  to  a  depth  of  1126  ft.,  it  having  been  enlarged  from  one  and  a  half  to 
two  compartments  below  the  noo-ft.  level.  In  sinking  to  that  depth  a  bucket 
and  crosshead  were  used,  but  cleaning  out  broken  rock  became  too  slow;  it 
took  41/2  minutes  to  hoist  and  return  a  bucket  when  the  shaft  was  that  deep. 
A  cage  and  car  were  therefore  substituted,  and  an  air-driven  hoist  installed 
on  the  noo-ft.  level.  Then  by  means  of  a  bucket,  which  dumped  into  a  bin 
on  that  level,  the  shaft  was  sunk  below  that  point  without  trouble,  as  sinking 
could  go  on  independently  of  the  surface  hoist,  at  least  up  to  the  capacity  of 
the  bin.  From  the  bin  the  rock  was  loaded  into  a  car  and  hoisted  to  surface 
on  the  cage.  This  made  a  gross  load  of  3500  Ib.  on  the  hoisting  rope,  which 
was  a  5/8-in.  Hercules  steel  rope,  weighing  62  1/2  Ib.  per  foot. 

Steam  Hoists  for  Shallow  Mines  (By  Sven  T.  Nelson). — Several  years 
ago,  in  the  iron-ore  fields  of  northern  Minnesota,  a  large  number  of  mining 
companies  were  hoisting  from  comparatively  shallow  depths  with  primitive 
slide-valve  engines  of  the  poorest  fuel  economy.  By  shallow  mines  are  meant 
those  from  200  to  1200  ft.  deep.  The  average  load  handled,  exclusive  of  the 
rope  and  skips,  is  5  tons,  and  ordinary  service  requires  a  speed  of  700  to  1000  ft 
per  minute. 

Some  30  years  ago  corliss  engines  or  engines  with  an  automatic  cut-off  were 
just  being  introduced  for  hoisting  purposes.  These  new  plants  were  chiefly  in 
the  Lake  Superior  copper  district.  They  consisted  largely  of  regular  mill  engines, 
purchased  from  the  corliss  engine  builders;  some  were  furnished  with  gear 
and  pinions  and  some  were  not.  The  drums  were  built  up  of  wood  at  the  mine. 

With  these  exceptions,  the  hoists  then  in  use  were  equipped  with  slide-valve 
engines  of  the  commonest  type.  Crude  as  were  the  first  corliss  hoists,  and 
numerous  as  were  the  objections  and  jibes  cast  at  them  on  account  of  their 
"trappy"  and  "complicated"  mechanism,  the  reduction  in  fuel  consumption 
which  they  secured  by  means  of  the  automatic  cut-off  was  so  great,  that  the 
slide-valve  engine  was  soon  crowded  from  the  field. 

The  iron  companies  of  the  northern  Michigan  field  were  also  impressed 
with  the  fact  that  corliss  hoists  did  their  work  on  from  one-third  to  half  the  fuel 
required  for  the  slide-valve  pattern.  The  first  engines  installed  at  any  of  the 
iron  mines  with  a  detachable  valve  gear  for  automatically  closing  the  steam 
valves  were  not  of  the  corliss  type,  but  of  the  same  type  as  an  engine  that  is 
still  built  at  Fitchburg,  Mass.,  by  the  Brown  Engine  Co.  A  modified  type  of 
the  Brown  engine  was  adopted  by  one  of  the  hoisting-engine  manufacturers  of 
that  time,  and  several  of  them  installed.  These  engines  were  found  to  be  satis- 
factory and  were  economical  on  low  steam  pressures.  However,  they  did  not 
lend  themselves  so  successfully  as  the  corliss  type  to  the  constant  increase  in 
steam  pressure,  which  took  place  with  improvements  in  boiler  manufacture. 

From  this  time  the  corliss  engine  became  the  standard  for  deep  hoisting 


HOISTING  AND  TRANSPORTATION 


203 


practice  throughout  the  Lake  Superior  region  and  the  western  mining  fields  as 
well.  By  deep  mines  are  meant  those  ranging  from  1000  to  5000  ft.  in  depth. 

With  the  knowledge  and  experience  gained  in  designing  hoists  for  deep 
mines  at  their  command,  the  engineers  attacked  the  problem  of  securing 
hoisting  economy  for  shafts  of  more  moderate  depths. 

It  is  out  of  the  question  to  use  first-motion  corliss  hoists  for  this  work,  on 
account  of  the  limitations  in  speed  of  corliss  valve  gear  requiring  engines  unduly 
large  for  the  service  required.  In  shafts  only  a  few  hundred  feet  in  depth 
after  the  load  is  accelerated,  but  a  few  revolutions  of  the  engine  will  be  made 
with  the  automatic  cut-off  in  action,  so  that  a  direct-acting  corliss  hoist  would 
be  not  only  needlessly  high  in  first  cost,  but  more  extravagant  in  fuel  than  a 
slide-valve  engine  of  the  simplest  type. 

Corliss-geared  hoists  were  tried  for  some  of  these  shallow  mines,  but  as  in 
the  case  of  first-motion  plants,  engines  disproportionately  large  had  to  be 
furnished,  to  keep  the  number  of  revolutions  as  low  as  possible.  Difficulty  was 
also  incurred  in  certain  fields,  in  securing  engineers  who  would  and  could  take 
proper  care  of  a  corliss  engine;  so  that  mine  managers  continued  to  use  the  old- 
fashioned,  plain  slide-valve  hoists,  with  their  excessive  cost  for  fuel. 

After  much  study,  the  type  of  hoist  known  as  the  automatic  slide-valve 
hoist  was  worked  out,  and  has  now  been  in  satisfactory  use  for  several  years. 

32  Revolutions  omitted,  all 
practically  the  same. 


Start  Bottom 


FIG.    134. CONTINUOUS    DIAGRAM   FROM  AN   AUTOMATIC   CUTOFF  HOISTING   ENGINE. 

That  this  design  fulfils  the  conditions  will  be  seen  readily  from  a  study  of  the 
continuous  indicator  diagram,  shown  in  Fig.  134,  taken  from  the  hoist  of  this 
pattern  at  the  Webb  mine  of  the  Shenango  Furnace  Co.,  at  Hibbing,  Minn. 

The  hoist  consists  of  two  slide-valve  engines  each  16X18  in.  geared  to  a 
single  drum  6  ft.  in  diameter  by  6  ft.  long.  It  takes  steam  at  145  Ib.  boiler 
pressure  and  runs  at  140  r.p.m.,  hoisting  a  load  of  5  tons  of  ore  in  addition  to 
the  weight  of  the  rope.  Two  skips  are  used  in  balance,  so  that  their  weight  is 
offset.  The  diagram  represents  the  entire  trip  from  the  start  at  the  bottom  to 
the  dump.  Each  diagram  indicates  one  revolution  of  the  engine.  The  gear 
and  pinion  ratio  is  four  to  one,  so  that  the  engines  make  four  revolutions  to  one 
of  the  drum.  As  there  are  57  diagrams  the  depth  of  the  shaft  is  269  ft.  and  the 
load  is  hoisted  in  14  revolutions  of  the  drum. 

In  starting  from  the  bottom,  it  should  be  noticed  that  the  first  diagram  takes 


204  HANDBOOK  OF  MINING  DETAILS 

steam  three-fourths  of  the  stroke,  the  second  about  five-eighths  of  the  stroke, 
and  the  third  about  one-third  of  the  stroke;  at  this  point  the  acceleration  is 
completed.  From  there  on,  up  to  the  point  referred  to  as  "collar  of  the  shaft," 
the  engine  is  cutting  off  at  about  one-fifth.  At  this  point  there  is  a  drop  in 
pressure,  as  indicated  by  the  diagram,  and  the  length  of  admission  of  steam  to 
the  cylinder.  When  this  point  is  reached,  the  engineer  closes  the  throttle 
partially  to  slow  up  for  the  dump ;  this  puts  the  automatic  cut-off  out  of  action,  in 
precisely  the  same  manner  as  the  dashpots  cease  to  drop  when  a  corliss  engine  is 
being  retarded.  From  the  point  called  "  collar  of  the  shaft"  to  the  point  referred 
to  as  the  "dump  and  finish"  the  regular  slide-valve  action  is  secured,  just  as 
would  be  the  case  for  the  entire  distance  from  top  to  bottom  were  it  not  for 
the  automatic  cut-off. 

The  three  individual  diagrams,  below  the  continuous  diagrams,  were  set 
aside  from  the  continuous  diagram  so  that  users  of  engines  not  familiar  with 
continuous  diagrams  can  tell  from  these  the  action  of  the  valve  gear  and  the 
steam  distribution.  The  slightly  jagged  appearance  of  the  lines  is  due  to  the 
high  speed  at  which  the  engine  was  running  and  a  small  amount  of  water  in 
the  indicator  pipes,  which  caused  the  indicator  pencil  to  chatter. 

It  should  be  noted  that  in  hoisting  engines,  hand  adjustment  of  the  point  of 
cut-off  is  out  of  the  question.  It  would  require  an  engineer's  constant  attention 
to  give  his  engine  steam  for  the  entire  stroke  when  starting  the  load,  to  set  the 
valves  at  the  proper  point  of  cut-off  when  the  load  is  under  full  motion,  and  to 
lengthen  the  cut-off  again,  at  the  end  of  the  trip.  This  is  obviously  impossible, 
nor  would  it  be  possible  for  the  engineer  to  set  the  cut-off  at  its  most  economical 
point  each  time,  owing  to  variations  in  steam  pressure  and  load. 

The  engines  of  the  Webb  mine  hoist  and  of  others  of  this  type,  are  of  the 
plain,  double,  slide-valve  pattern,  and  the  valve  gear  places  no  limit  on  the 
speed  at  which  they  can  be  run.  The  mechanism  controlling  the  automatic 
cut-off  is  so  arranged  that  no  extra  thought  or  action  is  required  of  the  engineer. 
When  the  throttle  lever  is  pulled,  the  first  2  or  3  in.  of  its  movement  opens  the 
main  throttles,  admitting  steam  during  the  entire  stroke  to  start  the  load  from 
the  bottom,  as  shown  by  the  first  cards.  As  the  lever  is  pulled  back,  it  admits 
steam  to  an  auxiliary  valve  mechanism  and  cylinder.  The  piston  of  this  cylinder 
actuates  a  crank  and  shaft  which  in  turn  moves  a  vertical  rack  at  the  rear  end 
of  each  cylinder.  These  racks  engage  pinions,  one  at  the  outer  end  of  each 
cut-off  valve  stem.  The  admission  of  steam  to  the  auxiliary  cylinder  therefore 
automatically  places  the  main  valves  in  the  position  of  shortest  cut-off,  and  this 
action  is  shown  in  the  cards  as  above  described.  At  the  end  of  the  trip,  the 
reversal  of  the  lever,  to  close  the  main  throttles,  admits  steam  to  the  opposite 
side  of  the  piston  in  the  auxiliary  cylinder,  and  the  cut-off  is  restored  to  its 
first  position. 

The  hoists  are  built  with  drums  ranging  from  6  to  8  ft.  in  diameter,  and 
with  engines  from  14 X 14  in.  to  16X24  in.,  adapted  for  steam  at  i5olb.  pressure. 


HOISTING  AND  TRANSPORTATION 


205 


The  hoisting  speeds  range  from  700  to  1000  ft.  per  minute  and  the  loads  from 
'5  to  7  tons. 

MISCELLANEOUS  DEVICES 

Sheave  Supports  for  Underground  Hoists. — At  the  Red  Jacket  shaft,  it 
is  necessary  to  work  the  lower  part  of  the  Calumet  &  Hecla  company's  ground 
by  means  of  a  blind  shaft  or  winze  that  starts  from  the  57oo-ft.  level  of  the 
Calumet  No.  2  shaft.  There  an  electric  hoist  is  installed  which  is  controlled 


Concrete 


FIG.    135. — SHEAVE   SUPPORT   IN   SHIFTING   GROUND. 

by  the  Ward  Leonard  system  of  wiring.  The  ground  around  the  station  has  a 
tendency  to  move  and  so  it  is  necessary  to  mount  the  sheaves  so  that  the  settling 
of  the  ground  will  not  cause  trouble.  This  is  done  as  shown  in  Fig.  135. 
Two  I-beams  are  put  together  as  posts  and  anchored  in  hitches  so  that  they 
will  stand  the  strain  coming  upon  them.  To  these  posts  are  bolted  maple  blocks, 
long  enough  to  extend  beyond  the  steel  posts  and  take  the  side  thrust  of  the 
sheave.  The  sheave  shaft  with  the  sheave  wheel  loosely  mounted  on  it  is  then 
bolted  tightly  in  its  seat  in  the  maple  blocks;  maple  blocks  are  also  used  as  cap 
pieces.  In  this  way  of  supporting  a  sheave  there  is  only  one  babbitted  bearing 
to  maintain,  while  the  main  feature  is  that,  in  case  either  post  should  move 
relatively  to  the  other,  the  wooden  blocks  will  adjust  themselves  to  the  change 
and  any  serious  trouble  be  promptly  remedied.  In  case  the  movement  is 


2O6 


HANDBOOK  OF  MINING  DETAILS 


great,  new  blocks  can  be  put  in  cheaply  and  the  shaft  lined  up  again.  If  two 
babbitted  bearings  are  used  in  this  ground  that  has  a  tendency  to  settle  and 
move,  endless  trouble  arises. 

Arrangement  of  Sheaves  at  the  Tobin  Mine. — In  Fig.  136  is  shown  the 
arrangement  of  sheave  wheels  that  had  to  be  adopted  at  the  Tobin  mine, 
Crystal  Falls,  Mich.,  in  order  to  use  the  hoisting  engine  without  turning  it 
around.  The  old  shaft  was  in  ground  that  will  eventually  be  mined  and  the 
new  shaft  was  sunk  1000  ft.  deep  in  the  foot  wall  and  back  of  the  engine  room. 
The  drums  are  8  ft.  in  diameter,  8  ft.  long  and  operated  by  a  Nordberg  engine. 


B 


Old  Shaft 


New  Shaft' 


FIG.    136. — ARRANGEMENT   OF  HOISTING   PLANT  AT   THE   TOBIN   MINE. 

The  sheave  wheels  which  are  anchored  in  front  of  the  engine  room  are  8  ft. 
in  diameter  and  held  in  place  by  i2-in.  framed  timbers  weighted  down  with 
rock.  While  these  additional  wheels  add  to  the  friction  losses,  no  trouble  has 
been  experienced  with  this  plan.  Three-ton  skips  are  hoisted  from  the  bottom 
of  the  shaft  in  30  sec.  The  wheels  at  A  are  incline.d,  to  conform  with  the  slope 
of  the  rope  to  the  top  of  the  shaft  house. 

Rope  Guard  for  Idler. — Trouble  is  often  experienced  in  keeping  hoisting 
ropes  on  their  idler  wheels,  especially  where  the  angle  to  the  sheave  wheel  is 
very  great.  This  can  be  overcome  by  means  of  the  simple  device  shown  in 
Fig.  137  which  is  in  use  in  many  mining  districts.  The  wheel  B  slides  hori- 
zontally on  its  shaft  to  allow  for  the  wind  on  the  hoisting  drum.  Unless  there 
is  ample  pressure  exerted  on  the  idler  wheel  by  the  hoisting  rope,  it  will  jump 
off;  and  especially  is  this  so  when  there  is  any  slack  in  the  rope.  Ropes  are 
supposed  to  keep  in  place  by  the  weight  of  the  rope  on  the  wheel,  the  idler 
wheels  being  placed  in  a  straight  line  with  the  sheave  wheel  and  the  drum  or, 
if  anything,  slightly  above  that  line.  In  using  this  device  it  should  be  placed 
in  a  straight  line  with  the  drum  and  the  sheave  wheel.  The  slotted  wheels, 
C  and  D,  are  held  in  place  by  two  straps  of  iron,  one  placed  on  each  side  of  the 
idler  wheel  B,  as  in  sketch.  The  bearing  edge  of  the  upper  wheels  should  be 
about  3/8  in.  above  the  hoisting  rope. 

Rope  Idlers  for  Inclined  Shafts. — In  the  conglomerate  shafts  of  the 
Calumet  &  Hecla  company  where,  owing  to  the  necessity  of  not  cutting  into 


HOISTING  AND  TRANSPORTATION 


207 


the  foot  nor  the  hanging  wall, ,  the  shaft  must  follow  the  lode  in  all  its  changes 
of  dip,  the  rope  idlers  or  rollers  are  subjected  to  severe  wear,  and  some  of  them 
have  to  be  replaced  once  per  shift,  while  the  average  life  of  an  idler  in  the 
whole  shaft  is  not  over  a  week.  It  is  important,  therefore,  to  make  the  idlers 
in  a  cheap  and  simple  way.  They  are  maple  logs  turned  down  to  a  diameter 
of  1 6  in.  and  a  face  of  24  in.,  in  which  three  grooves  are  turned  along  which 
the  cable  may  run  as  the  idler  is  shifted  in  the  shaft.  Through  the  center 


FIG.    137. — IDLER  WHEELS   FOR  HOISTING  ROPES. 

of  the  idler  a  i  i/2-in.  hole  is  bored  for  the  axle.  Formerly  an  iron  pipe  was 
inserted  in  the  idlers  for  a  thimble  and  the  idler  revolved  on  a  fixed  axle. 
This  arrangement  is  the  cheaper  and  is  good  enough  for  shallow  shafts  where 
the  hoisting  speed  is  not  great,  but  there  is  too  much  friction  to  use  such  idlers 
with  high  rope-speeds  as  it  is  impossible  to  grease  them  properly.  The  idlers 
now  generally  used  have  a  fixed  axle  that  rests  in  two  bearings  on  the  idler 
frame  which  is  wedged  in  place  in  the  shaft  between  the  cedar  ties  of  the 


I 


gide  Elevation 


Section 
FIG.    138.  —  IDLER   FOR  SKIP   ROPE   IN  SHAFTS. 

skip  tracks.  These  frames  are  set  in  the  shaft  so  that  the  rope  passes  through 
the  right-hand  groove  of  one  idler,  the  center  groove  of  the  next  and  the  left- 
hand  groove  of  the  next.  By  changing  the  idlers  from  one  frame  to  another 
they  may  be  completely  worn  out. 

This  type  of  idler  is  used  in  the  amygdaloid  mines  of  the  district,  except  at 
the  shafts  of  the  Osceola  Consolidated,  where  a  built-up  idler  is  used.  This 
idler,  as  the  amygdaloid  shafts  are  sunk  at  a  regular  dip,  does  not  have  to  be 


208 


HANDBOOK  OF  MINING  DETAILS 


made  so  wide  to  insure  the  rope  staying  on  the  idler,  while  as  the  wear  is  not 
so  great  as  in  the  conglomerate  shafts,  the  idler  part  is  built  up  of  segments 
so  that  the  wear  will  come  end-on  instead  of  sidewise  with  the  fiber  of  the  wood. 
These  built-up  idlers  are  18  in.  diameter  and  10  in.  wide.  There  are  three 
layers  of  octant  segments  held  together  by  flanges  and  bolts  through  the  apex 
of  each,  as  shown  in  Fig.  138.  The  outer  segments  are  sawed  from  4 X6-in. 
maple  or  beech  planks,  being  cut  so  that  the  grain  runs  approximately  length- 


6-  5/8-in.  Bolts 


Pipe  Tap 


FIG.    139. — IDLER   FOR  HOISTING   ROPES    USED   AT   CHAMPION   MINE. 

wise,  while  the  inside  segment,  the  one  that  takes  the  wear,  is  sawed  from  a 
2X6-in.  plank  of  the  same  material.  It  is,  therefore,  possible  to  replace  the 
segments  without  throwing  away  the  whole  idler  when  only  a  few  of  the  seg- 
ments in  a  layer  are  worn.  The  outer  segments  are  made  with  a  shoulder 
1/2  in.  deep  turned  in  them  to  receive  the  flanges  so  that  the  bolts  that  run 


HOISTING  AND  TRANSPORTATION 


209 


through  the  idler  will  not  extend  beyond  the  sides  to  wear  and  cut  the  rope  in 
case  it  should  slip  off  the  idler.  These  idlers  have  been  in  use  several  years. 
They  last  much  longer  than  do  the  other  types,  and  as  they  are  lighter,  they 
get  up  to  speed  when  the  rope  comes  on  them  quicker  than  do  the  others.  In 
the  conglomerate  mines  they  cannot  be  used,  because  the  wear  is  so  great 
that  it  does  not  pay  to  try  to  increase  the  life  of  the  idlers  by  complicating  the 
design. 

Idler  for  Hoisting  Rope  in  Inclines. — In  the  shafts  of  the  Copper  Range 
company  in  Michigan  which  have  a  dip  of  about  70°,  the  hoisting  ropes  are 
carried  on  wood-lined  idler  sheaves  at  intervals  of  about  33  ft.  The  idler,  as 
shown  in  Fig.  139,  is  made  of  two  malleable-iron  castings  bolted  together  to 
grip  the  wood  lining  pieces  in  the  jaws  of  the  wheel.  On  the  jaws  are  cast 
two  beadings  for  cutting  into  the  wood  and  holding  it  tightly.  The  wood 


FIG.    140. — DEVICE   TO    PREVENT   OVERWINDING. 

filling  pieces,  which  are  sawed  so  that  they  take  the  wear  on  the  ends  of  the 
fibers  on  the  wood,  are  in  two  pieces  arranged  so  as  to  stagger  the  joints  between 
the  segments  of  each  half  of  the  lining.  These  segments  are  cut  so  as  to  have 
a  'chord  of  about  6  in.  across  their  outer  face.  The  wood  pieces  should  be 
sufficiently  thick  so  that  when  the  nuts  are  brought  tightly  home  on  the  bolts 
the  two  pieces  of  the  frame  will  not  quite  touch.  Then  the  bolts  can  be  tight- 
ened so  that  the  pieces  of  wood  will  be  held  securely  even  if  they  shrink.  Owing 
to  the  fact  that  the  hoisting  cable  does  not  have  much  side  play  in  these  shafts, 
a  face  of  4  1/2  in.  on  the  idlers  is  sufficiently  wide.  The  rim  of  the  casting  is 
14 


2io  HANDBOOK  OF  MINING  DETAILS 

much  wider  than  the  spokes  so  the  bolts  that  hold  the  frame  pieces  together  are 
well  within  the  protection  of  the  rim  and,  in  case  the  rope  should  slip  off  the 
idler,  it  would  not  come  in  contact  with  the  nuts  on  the  clamping  bolts.  The 
bearings  for  the  idlers  rest  on  I-beams  carried  on  concrete  pedestals  from  the 
bottom  of  the  shaft,  and  the  whole  frame  is  in  turn  protected  from  injury  by 
the  skip  by  means  of  wooden  buffer  pieces  running  along  over  the  main  I-beams 
and  in  turn  carried  on  I-beam  crosspieces. 

Device  for  Prevention  of  Overwinding. — The  device  shown  in  Fig.  140 
is  installed  at  a  German  shaft  to  prevent  overwinding.  At  a  point  about 
30  cm.  above  the  highest  normal  position  of  the  cage  is  pivoted  an  axle,  carrying 
at  its  center  a  lever  A,  which  projects  out  into  both  hoisting  compartments, 
and  at  its  end  the  pulley  B,  to  which  a  length  of  chain  is  attached  at  two  points, 
as  shown.  The  middle  point  of  this  chain  is  connected  to  a  wire  rope  which, 
after  passing  over  the  pulley  D,  hangs  down  a  suitable  distance  and  is  kept 
taut  by  the  weight  E.  A  short  piece  of  rope  F  connects  the  first  rope  with  an 
end  of  the  latch  G,  which  engages  the  top  of  the  lever  H.  The  rope  /  attached 
to  H,  leads  to  the  throttle  valve  of  the  engine,  and  also  to  the  valve  of  a  steam- 
actuated  brake.  A  slight  upward  pressure  against  either  end  of  the  lever  A 
thus  lifts  the  latch  G,  allowing  the  weight  J  to  act  through  the  rope  7  on  the 
engine.  The  same  effect  could  be  produced  electrically,  though  possibly  not 
with  equal  certainty,  by  establishing  contact  through  the  guide  shoes  of  the 
cage,  and  providing  a  magnetic  release  for  the  latch  G. 

Device  for  Cleaning  Flat  Wire  Cables  (By  M.  J.  McGill). — An  arrange- 
ment that  I  have  used  successfully  for  cleaning  hardened  grease,  dirt  and  rust 
from  flat  wire  cables  is  illustrated  in  Fig.  141.  The  contrivance  consists  of  a 
box  made  in  four  parts  to  be  hooked  and  stapled  together,  in  which  is  fastened 
a  U-shaped  steam  fitting  through  which  the  cable  is  passed.  The  bottom  of  the 
box  is  first  placed  on  a  platform  above  the  collar  of  the  shaft,  the  cage  or  skip 
being  lowered  just  far  enough  so  as  to  clear  all  the  cable  fastenings.  A  fitting 
B,  made  as  shown  in  the  drawing,  with  two  i-in.  pipe  legs  with  i/i6-in.  slots 
and  capped  ends,  is  placed  with  one  leg  on  each  side  of  the  cable,  the  slots  being 
turned  a  trifle  downward.  The  top  parts  of  the  box  are  then  placed  and  hooked 
to  the  bottom  parts.  An  opening  just  large  enough  to  admit  the  fitting,  so  as  to 
make  it  as  near  grease  tight  as  possible,  is  made  -in  the  side  of  the  box.  A 
steam  line  is  coupled  to  the  fitting  B,  and  the  steam  turned  on,  while  the  cage 
is  slowly  dropped.  As  the  cage  drops,  the  cable  passes  through  the  steam 
fitting,  and  being  subjected  to  the  scrubbing  action  of  live  steam  is  readily 
cleaned.  The  time  required  to  clean  thoroughly  depends  on  the  condition  of 
the  cable.  A  few  minutes  after  applying  the  steam,  grease  and  dirt  will  begin 
rolling  over  the  blocks  C  C,  which  are  placed  across  the  inside  of  the  box  to 
strengthen  it  and  to  divert  grease  toward  the  nipples  at  the  end  of  the  box, 
from  which  it  falls  into  buckets  placed  to  receive  it. 

In  three  hours'  time  I  have  thoroughly  cleaned  1500  ft.  of  the  worst-looking 


HOISTING  AND  TRANSPORTATION 


211 


cable  that  one  can  imagine.  Some  cables  of  equal  length  that  were  not  in 
such  bad  condition  only  required  1/2  hour.  This  apparatus  has  proved 
superior  to  any  I  have  seen  or  read  of  for  thoroughly  cleaning  flat  wire  cables. 
I  always  lubricate  the  cable  immediately  after  cleaning. 

Mine  Signal  Switch. — A  mine  signal  switch  designed  by  A.  H.  MacGregor, 
Palatka,  Mich.,  is  shown  in  Fig.  142.  The  principal  feature  in  this  switch  is 
that  it  is  strong  and  not  likely  to  get  out  of  order  as  does  a  more  delicate  one 
under  the  rough  usage  of  the  miner.  The  parts  are  mounted  upon  a  hardwood 
board,  1X8X16  in.,  and  inclosed  within  a  box  as  shown  by  the  dotted  line. 
The  switch  lever  is  of  3/16X1  i/4-in.  steel  upon  which  a  copper  contact  is 
.soldered.  The  lever  is  pivoted  at  B  and  is  held  in  position  by  a  bar  A ,  which 
prevents  any  side  movement.  The  copper  bar  C  is  in  contact  with  the  lever  at 


i'w.i.  Pipe 


2  W.I.  Pipe 


FIG.    141. — CLEANING  DEVICE   FOR   FLAT- WIRE   CABLES. 

all  times.  The  circuit  is  completed  with  the  contact  C '.  A  No.  10  tension 
spring  breaks  the  circuit  as  soon  as  the  operator  releases  the  handle  D.  The 
switch  is  placed  about  elbow  high  so  that  it  requires  some  effort  to  operate  it. 
In  this  way  the  contacts  are  positive  and  distinct,  and  there  is  no  fluttering  as  is 
the  case  when  a  switch  is  in  such  a  position  that  it  can  be  operated  rapidly. 
The  board  and  handle  D  are  covered  with  an  insulating  paint.  The  device  has 
been  in  use  over  a  year  and  is  now  installed  at  several  of  the  Pickands-Mather 
mines. 

Another  type  of  spring  switch  used  in  connection  with  an  electric  signal 
system  is  shown  in  Fig.  143.  It  is  built  in  a  metal  box  6X  ioX  5  in.  deep  with  a 
hinged  door  on  one  side.  When  giving  signals  the  operator  catches  hold  of  the 


212 


HANDBOOK  OF  MINING  DETAILS 


wooden  handle  that  hangs  below  the  box,  pulls  down,  and  the  spring  in  the  box 
breaks  the  circuit  as  soon  as  the  operator  releases  his  hold.  Th?  signal  system, 
which  is  used  in  connection  with  this  switch,  flashes  a  light  in  addition  to 
ringing  the  gong. 

Electric  Signals  for  Underground  Tramways  (By  W.  S.  Grether). — 
Fluorspar  associated  with  galena  occurs  in  a  vein  near  Rosiclare,  on  the  Ohio 


PIG.    142. — SIGNAL  SWITCH  AT  BALTIC   MINE,   MICH. 


.Ineulatlod. 


6  in. 


ard  Rubber  Mnsulation 


Wood  Handle 


FIG.    143. — SPRING   SWITCH   FOR   ELECTRIC   MINE   SIGNAL. 

River,  in  southern  Illinois.  The  vein  has  been  prospected  for  a  length  of  2  or 
3  miles  and  to  a  depth  of  500  ft. ;  it  is  from  3  to  20  ft.  wide.  In  mining  the  ore 
is  cleanly  broken  from  the  foot  and  hanging  walls  and  not  more  than  10% 
of  the  ground  broken  is  waste.  The  drifts  are  tortuous  and  not  of  uniform 
width  which  makes  electric  haulage  impracticable  on  the  235-ft.  or  main  working 
level. 

The  ore  is  mined  by  overhand  stoping  and  the  i-ton  tram  cars  are  loaded 


HOISTING  AND  TRANSPORTATION 


213 


from  wooden  bins  situated  20  ft.  apart  along  the  single  track  in  the  drift.  The 
cars  are  moved  by  men  to  the  three-compartment  shaft  sunk  midway  between 
the  ends  of  the  vein;  mules  are  used  to  pull  the  empties,  10  cars  per  trip,  back 
to  the  loading  bins  The  excessive  grade  of  the  drift,  i  1/2%,  prohibits 
hauling  the  loaded  cars  with  mules.  Ore  is  trammed  from  either  end  of  the 
mine,  one  end  being  called  the  south,  the  other  the  north  workings.  The 
caging  at  the  shaft  is  often  delayed  on  account  of  wrecks,  lowering  timbers,  etc. 
The  trammers  in  the  ends  of  the  workings  perhaps  2000  ft.  away  are  not  aware 
of  these  conditions  and  formerly  continued  to  bring  cars  to  the  shaft,  making 
matters  worse  on  account  of  the  limited  switching  facilities  near  the  old  station. 
To  overcome  this  difficulty  a  simple  electric  signal  system  was  installed. 


.  Where  magnified 

•  •  •           -*  — 

/^\ 

(0,\^ 

under  strong  Light. 

v~7-^^ 

Green  Light 

BELL  SIGNALS 

Flash  . 

, 

—  ~^-  —  ~  _T_ 

1 

_~               ~_ 

_^=S5>. 

.Electric  Bell  actuated 

©~ 

by  Fulling  a  Handle 
in  Mine. 

i 

FIG.    144. — A   GERMAN   SIGNALING   DEVICE. 

A  switch  and  two  no-volt,  i6-c.p.  lamps,  one  green  and  one  white,  are 
placed  on  the  south  side  of  the  shaft,  and  similar  equipment  is  installed  in  the 
south  workings  near  the  loading  bins.  Similarly,  switches  and  red  and  white 
lights  are  placed  on  the  north  side  of  the  shaft  and  in  the  north  workings. 
All  switches  are  left  open  except  when  signals  are  being  sent.  When  the  eager 
wants  cars  at  the  shaft  he  closes  the  switch  three  times.  The  trammer,  when 
ready  to  move  cars  to  the  shaft,  answers  with  three  signals.  Likewise  when 
the  trammer  wishes  to  push  cars  to  shaft,  he  signals  three  flashes  to  the  eager; 
if  the  eager  is  ready  he  flashes  three  in  return.  In  this  way  blockades  at  the 
shaft  are  avoided  and  the  trammer  may  utilize  his  time  while  waiting  for  signals 
in  oiling  cars  or  cleaning  the  track. 

An  Electric  Signal  Device  (By  P.  B.  McDonald).— Two  German  signal 
devices  for  hoisting,  the  general  scheme  of  operation  of  which  is  shown  in  Fig. 
144,  have  been  installed  in  the  Negaunee  mine  hoist  house.  When  a  man  in 


214 


HANDBOOK  OF  MINING  DETAILS 


the  mine  pulls  the  signal  handle,  two  things  happen  in  the  engine  room.  The 
electric  bell  rings  and  a  strip  of  paper  resembling  a  stock  exchange  ticker  tape 
is  punched  with  a  hole.  By  means  of  a  strong  magnifying  device  and  mirrors, 
a  magnified  reflection  of  the  small  hole  punched  in  the  strip  of  paper  appears  in 
a  horizontal  aperture.  Thus  if  the  hoist  engineer  is  not  sure  of  the  number  of 
bells  which  were  rung,  a  glance  at  the  black  circles  tells  him,  also  the  strip  of 
paper  serves  as  a  permanent  record  in  case  a  dispute  arises  as  to  the  signals 
that  were  given.  In  addition  to  these  electric  signal  devices  the  old  style 
mechanical  bell  will  probably  be  ins-tailed,  for  use  when  the  electrical  apparatus 
is  out  of  order.  The  green  light  flashes  only  when  the  paper  strip  of  the  punch- 
mark  mechanism  is  exhausted. 

Hand  Bell  Signal  Wiring  (By  Guy  C.  Stoltz). — The  disadvantages  of 
hand  signaling  are:  The  difficulties  presented  in  counterbalancing  the  long  line 


6x6  Purlin 

,"x2Vi'  Spring  Steel 


Arrangement  at  Hoist  House 


Guide  for 
Skip    — 

Wire  down 
-    Shaft 


Guides  for  Bell 
Wire  through  Shaft 


Arrangement  at  Shaft  House 

FIG.    145. — ARRANGEMENT   OF   SIGNAL-BELL   WIRING   AT   PORT  HENRY,    N.    Y. 


of  bell  wire  necessary  to  reach  the  lowest  levels  in  the  shaft;  in  guiding  the  wire 
through  the  shaft  over  the  several  angles  to  the  stations  and  to  the  hoist  house 
with  the  least  friction;  and  in  keeping  the  system  taut  to  eliminate  all  possible 
lost  motion.  The  system  installed  must  be  positive  and  hand  ringing  should 
accompany  every  electric  bell  or  light- signaling  installation.  In  Fig.  145  a 


HOISTING  AND  TRANSPORTATION  215 

satisfactory  method  of  rigging  is  shown.  The  strap  of  spring  steel  introduced 
before  the  gong  does  away  with  any  lost  motion  to  the  gong  and  keeps  the  wire 
taut  to  the  counterbalanced  triangle  at  the  headframe.  Here  the  wire  is  kept 
on  a  winch  and  the  necessary  length  is  guided  over  a  small  pulley  to  prevent 
kinks,  and  down  the  shaft  by  cranking  the  winch.  A  grip  is  clamped  to  the 
wire  after  the  required  length  has  been  unreeled,  and  this,  bearing  against  the 
triangle,  makes  the  wire  fast.  In  this  way  the  wire  is  kept  one  length  with  no 
splicing  and  as  longer  wire  is  required  on  sinking,  the  winch  has  a  supply. 
Hand-holds  for  signaling  are  clamped  to  the  wire  at  each  station.  The  wire 
is  guided  through  the  shaft  by  passing  between  sets  of  2  i/2-in.  pulleys  placed 
in  an  iron  frame.  This  frame  is  secured  to  the  shaft  timbers.  The  counter- 
weight is  attached  to  the  triangle  in  the  headframe  and  is  varied  in  amount  as 
required. 

AERIAL  TRAMWAYS 

The  Solution  of  a  Cableway  Hoist  Problem. — At  Mine  21,  Mineville, 
N.  Y.,  the  greater  part  of  the  ore  in  the  open  pit  was  hoisted  and  carried  to  the 
gondola  cars  on  the  surface  by  means  of  a  Lidgerwood  traveling  suspension 
cableway.  The  towers  on  opposite  sides  of  the  pit  were  400  ft.  apart,  the 
greatest  hoisting  depth  300  ft.  vertically,  and  the  carriage  was  usually  carried 
out  about  200  ft.  where  the  bucket  was  dumped  by  hand.  Some  time  after 
installation  and  as  hoisting  depth  increased  the  scoop  on  being  raised  began  to 
rotate  in  mid  air,  twisting  the  fall  block  cables  and  throwing  out  most  of  the 
ore.  The  problem  as  to  how  to  guide  the  scoop  in  its  upward  journey  required 
some  little  attention.  Many  schemes  were  suggested  and  many  were  tried. 
A  leading  rope  manufacturer  recommended  trying  his  non-twist  rope.  This 
was  given  a  trial  but  did  not  help  matters  in  the  least.  The  master  mechanic 
finally  devised  the  following  scheme.  An  i8-in.  arm  was  attached  to  the 
fall  block  frame  and  from  this  a  5/i6-in.  wire  rope  was  run  over  two  i2-in. 
sheaves  (spaced  10  ft.  apart  center  to  center  and  hung  by  a  frame  to  the  traveling 
cable)  and  then  to  an  overhanging  light  counterweight.  The  rope  and 
counterweight  proved  to  be  a  satisfactory  guide.  In  fact  the  rope  alone  was 
sufficient  to  steady  the  scoop  during  the  ascent,  the  only  part  played  by  the 
counterweight  being  to  keep  the  small  rope  taut  so  it  would  travel  well  over  the 
auxiliary  sheaves.  Besides  preventing  the  twisting  of  the  block  this  arrange- 
ment also  serves,  to  some  extent,  to  prevent  the  load  from  swinging. 

Turning  Device  for  Tramway  Track  Cables. — The  companies  that 
erect  tramways  instruct  that  the  track  cable  be  frequently  turned  so  as  to 
equalize  the  wear,  but  this  has  proved  to  be  a  direction  easier  to  give  than  execute. 
For  instance,  at  the  United  States  tramway  at  Bingham,  the  tramway  men 
tried,  without  success,  for  over  a  year  to  turn  the  cable. 

The  directions  usually  given  by  manufacturers  are  for  twisting  the  cable 
by  means  of  stilson  wrenches.  Sections  of  the  cable  can  easily  be  turned,  but 


216  HANDBOOK  OF  MINING  DETAILS 

the  difficulty  is  to  make  the  cable  stay  in  the  new  position,  for  if  not  held  it 
gradually  works  back  to  the  old  position.  To  obviate  this  difficulty,  Joseph 
Ruttle,  foreman  of  the  Highland  Boy  tramway,  Bingham,  Utah,  has  devised  a 
method  of  turning  and  holding  the  cable  that  is  certain  in  its  operation.  The 
device  for  accomplishing  this,  known  as  the  Ruttle  turning  strap,  has  been  in 
use  some  time,  and  it  is  probably  as  much  due  to  its  use  as  to  any  other  one 
cause  that  the  old  Highland  Boy  tramway  was  noted  for  the  long  life  of  its  track 
cables. 

The  turning  strap  consists  of  an  iron  strap  2  1/2  in.  wide,  made  of  No.  12 
band  steel  that  is  clamped  to  the  track  cable  by  means  of  two  T-head  bolts, 
which  have  their  flat  heads  turned  toward  the  passing  buckets.  This  band 
steel  is  continued  to  form  an  arm  12  in.  long,  and  then  a  3/4-in.  round  rod  is 
bolted  to  the  end  of  this  arm  between  two  nuts  working  on  a  right-  and  left- 
handed  threads.  In  order  to  prevent  the  outer  bolt  from  working  off  and 
allowing  the  arm  of  the  clamping  strap  to  swing  around  and  catch  on  the 
bucket,  a  cotter  pin  is  inserted  in  a  hole  drilled  through  the  end  of  the  rod. 
This  rod  is  made  long  enough  to  pass  through  a  detaining  brace,  or  loop, 
which  is  made  by  bending  double  a  3/4-in.  round  rod.  The  iron  loop  is  just 
wide  enough  for  the  arm  of  the  turning  clamp  to  move  freely  back  and  forth, 
with  the  stretch  of  the  cable,  and  is  made  3  ft.  long,  so  as  to  provide  for  that 
much  stretch.  The  detaining  brace,  or  loop,  is  fastened  by  means  of  two 
3/8X4-in.  lag  screws  to  the  timbers  of  the  tower,  the  rod  being  flattened  to 
3/8  in.  where  it  comes  in  contact  with  the  tower  timbers.  The  turning  straps 
are  put  on  the  track  cable  at  each  tower. 

Whenever  it  is  observed  that  the  track  cable  is  wearing,  or  about  once  in 
two  weeks,  the  cable  is  turned  one-eighth  way  around  by  means  of  stilson 
wrenches,  the  clamping  bolts  on  the  turning  clamps  having  been  previously 
loosened.  Then  the  clamps  are  again  tightened  on  the  cable.  Needless  to 
say,  the  twisting  must  be  done  in  the  direction  of  the  twist  of  the  cable,  or  else 
the  strands  will  be  unlaid. 

Cable  Clamp  for  Tramway  (By  Claude  T.  Rice). — Tramway  cables  have 
to  be  frequently  stretched,  especially  in  the  early  period  of  the  operation  of 
a  tramway.  This  is  a  troublesome  task,  owing  to  the  design  of  the  cable 
clamps  in  common  use.  The  clamp  furnished  by  the  tramway  companies  is 
made  of  two  iron  plates,  with  a  shallow  central  groove  to  increase  the  contact 
and  consequently  the  friction  of  a  cable  when  the  clamp  is  tightened.  At  the 
end,  the  two  plates  are  given  an  outward  bend,  so  as  to  keep  apart  the  ropes 
that  are  fastened  to  the  plates  of  the  clamp.  Two  different  strands  of  the 
block  and  tackle  system  are  attached  to  the  twisted  lengths  in  the  ends  of  the 
two  clamping  plates.  Thus  there  is  little  if  any  clamping  effect  obtained 
from  the  pull  of  the  ropes,  the  entire  pressure  of  the  cable  being  obtained 
from  the  tightening  of  the  six  bolts  that  hold  the  plates  together. 

On  the  traction  cable  this  design  of  clamp  holds  fairly  well,  but  with  the 


HOISTING  AND  TRANSPORTATION 


217 


r—^f— *i 


rr^'T 
Wi 


2i8  HANDBOOK  OF  MINING  DETAILS 

heavier  track  cables  it  does  not  give  satisfaction.  Joseph  Ruttle,  foreman  of  the 
Highland  Boy  tramway  at  Bingham,  Utah,  has  devised  the  clamp  that  is  now 
in  general  use  at  Bingham.  This  clamp  is  simple  in  design,  effective  in  its 
operation,  easy  to  put  on  the  cable,  even  by  one  man,  and  can  be  cheaply 
made  in  any  machine  shop.  This  clamp  is  caused  to  grip  by  the  pull  of  the 
tightening  tackles  and  so  is  correct  in  principle.  The  tramway  man  has  only 
to  give  the  grip  pieces  a  slight  blow  to  cause  an  initial  grip  on  the  cable.  In  case 
the  clamp  should  be  put  on  at  a  point  where  the  cable  is  larger  than  elsewhere, 
and  there  should  be  any  slipping,  the  clamp  adapts  itself  to  the  diminishing 
diameter  of  the  cable  and  grasps  the  cable  more  securely  than  ever.  This 
device  is  unpatented  and  has  been  in  use  on  the  Bingham  tramway  for  at 
least  a  year. 

The  Ruttle  clamp  consists  of  a  base  plate  A,  referring  to  Fig.  146,  with 
raised  sides,  to  which  are  bolted  two  cover  plates  B  that  partly  cover  the  top 
of  the  base  plate.  The  sides  of  the  base  plate  taper  toward  the  rear  end,  so, 
as  the  clamping  pieces  C  move  along  the  channels  formed  by  the  base  plates, 
they  are  forced  nearer  together  and  grip  the  cable  more  securely.  The  base 
plate  has  a  curved  neck,  to  which  the  blocks  are  attached  by  a  ring.  The 
clamping  pieces  have  the  face  toward  the  cable  turned  to  the  diameter  of  the 
cable  on  which  the  clamp  is  to  be  used,  but  by  having  other  sets  of  grips  the 
clamp  can  be  quickly  changed  so  as  to  be  used  on  larger  or  smaller  cables. 
The  faces  of  the  grips  are  segments  of  a  cylinder,  so  they  adapt  themselves 
to  the  cable  when  it  is  considerably  worn. 

In  order  to  hold  the  grip  pieces  in  the  channels  in  which  they  travel,  a 
hemispherical  pocket  is  bored  in  the  grip  piece  to  receive  a  3/8-in.  steel  ball, 
while  in  the  base  plate  a  cylindrical  groove  is  cut  under  each  cover  plate,  in 
which  the  steel  ball  may  travel.  This  groove  is  made  long  so  the  grip  pieces 
may  spread  far  enough  apart  at  the  head  end  to  facilitate  placing  the  clamp 
on  the  cable.  When  the  grip  piece  is  in  its  farthest  position  at  the  other  end 
of  the  groove,  its  two  faces  are  considerably  nearer  together  than  the  diameter 
of  the  rope.  The  angle  given  to  the  back  raised  edge  of  the  base  plate  deter- 
mines the  length  of  the  groove,  while  the  angle  of  the  back  edge  and  length 
of  the  base  plate  itself  are  determined  by  the  length  of  gripping  surface  that 
is  necessary  to  give  a  secure  hold  on  the  cable. 

Oiling  Tramway  Track  Cables. — The  machine  used  to  oil  the  track 
cables  on  the  Balaklala  aerial  tramway,  at  Coram,  Calif.,  consists  of  a  carrier 
frame  arranged  to  carry  an  oil  tank  having  a  capacity  of  10  gallons.  This 
carrier  frame  is  fastened  to  a  set  of  trolley  wheels  turned  upside  down,  so  as 
to  secure  a  space  between  the  wheels  for  the  oil  jet  directly  over  the  track 
cable.  There  are  two  gear  wheels,  one  of  which  is  mounted  on  the  extended 
axle  of  one  of  the  trolley  wheels  and  the  other  secured  to  the  trolley  frame 
and  carrying  a  wheel  for  the  belt  running  the  rotary  oil  pump  which  is  mounted 
on  the  tank.  By  these  gear  wheels  the  speed  of  the  oil  pump  is  regulated. 


HOISTING  AND  TRANSPORTATION  219 

By  means  of  a  cock  in  the  pipe  leading  to  the  oiler  the  supply  of  oil  to  the 
cable  is  controlled.  After  a  rain  the  supply  is  so  regulated  that  enough  oil 
is  fed  to  run  down  and  cover  all  the  cable,  while  at  other  times  the  supply  is 
only  enough  to  cover  the  upper  side.  When  the  valve  has  been  properly 
regulated  to  give  the  right  amount  of  oil,  the  carrier  is  gripped  to  the  traction 
rope  and  the  automatic  oiler  is  sent  out  over  the  line.  This  oiler  works 
satisfactorily  at  the  Balaklala  mine  where  it  was  designed. 

Oiler  for  Tramway  Buckets. — It  is  necessary  to  oil  the  wheels  on  the 
carriers  on  tramways,  especially  new  ones,  frequently.  Moreover,  the  amount 
of  oiling  necessary  seems  to  bear  some  relation  to  the  roughness  of  the  topog- 
raphy of  the  country  across  which  the  tramway  is  built.  In  the  early  stages 
of  the  life  of  a  tramway  two  miles  long,  it  is  necessary  to  oil  the  buckets  every 
trip,  and  later  at  least  twice  a  day,  while  with  tramways  four  miles  long  the 
bucket  carriers  have  to  be  oiled  at  least  every  other  trip.  This  oiling  can  be 
done  at  either  end  of  the  tramway,  but  generally  it  is  far  more  convenient  to 
do  the  oiling  at  the  loading  station,  while  the  bucket  is  being  loaded. 

The  usual  arrangement  is  to  have  a  tank  of  oil  placed  at  some  convenient 
point  above  the  loading-track  station  so  that  enough  fall  is  given  to  the  oil 
to  insure  a  quick  feeding  of  it  to  the  carrier  wheels.  The  oil  is  led  through 
a  small  rubber  tube  to  the  metallic  tip  used  for  insertion  into  the  oil  holes  on 


Top  End 

E  B      A  -  Vv1Tef 

FIG.    147. — NONLEAKING   OILER  FOR  TRAMWAY  BUCKETS. 

the  wheels  of  the  carrier  carriage.  To  shut  off  the  feed  of  oil,  a  spring  clamp 
or  pinch  cock  is  generally  used  on  the  feed  tube.  Besides  being  inconvenient 
this  is  wasteful,  for  most  of  the  oil  in  the  tube  below  the  point  of  clamping 
drops  out  while  the  tip  is  being  transferred  from  one  oil  hole  to  another.  This 
waste  of  oil  is  not  only  a  source  of  needless  expense,  but  it  increases  the  danger 
from  fire,  and  in  time  makes  the  loading  station  a  greasy,  sloppy,  disagreeable 
place. 

To  obviate  these  objections,  W.  H.  Cole,  master  mechanic  at  the  Highland 
Boy  mine,  Bingham,  Utah,  devised  the  oiler  shown  in  Fig.  147.  The  Cole 
oiler  is  attached  to  a  feeding  hose  just  as  the  tip  is  in  the  crude  device  commonly 
used.  But  in  this  oiler  the  oil  cannot  be  turned  on  until  the  oiler  has  been 
inserted  to  the  bottom  of  the  oiling  hole,  and  the  feed  is  shut  off  the  instant  that 
the  pressure  is  taken  off  the  oiler.  As  a  result  there  is  no  wasting  of  oil  and 
the  accompanying  disagreeable  features  are  eliminated.  In  addition,  the  oiling 
can  be  done  quickly  and  easily. 

The  oiler  is  turned  out  of  two  pieces  of  brass  A  and  A',  to  form  the  shell, 


22O 


HANDBOOK  OF  MINING  DETAILS 


while  the  interior  mechanism  consists  of  a  spring  valve  B,  working  upon  a  valve 
seat  C.  Leak  about  the  valve  is  prevented  by  three  oil  rings  D,  in  which  no 
packing  is  used,  as  whatever  oil  may  ooze  down  the  valve  rod  forms  its  own 
natural  packing  at  these  grooves.  The  barrel  is  i  in.  in  diameter,  4  in.  long 
and  the  surface  is  milled  to  render  it  easy  to  grip.  The  surface  of  the  piece 
A'  that  fits  into  the  rubber  hose  is  corrugated  to  aid  in  attaching  the  oiler  securely 
to  the  feed  hose.  The  valve  has  a  play  of  3/8  in.,  and  the  stem  is  fluted,  the 
upper  end  of  the  stem  being  sharpened  so  as  to  assist  the  feed  of  the  oil  into 
the  oil  chamber  E,  when  the  valve  is  opened.  The  discharge  hole  in  the  valve 
tip  F  is  bored  to  5/32  in.,  connection  with  the  oil  chamber  being  through  the 
hole  G,  bored  at  right  angles  to  the  discharge  hole. 

When  the  tip  of  the  oiler  is  pressed  against  any  resisting  surface,  as  the 
bottom  of  the  oil  hole  on  the  carrier  wheels,  the  valve  is  forced  back  against 


FIG.    148. — WIRE-ROPE  ANCHORAGE. 

the  shoulder,  and  oil  flows  from  the  oil  chamber  in  the  oiler  through  the  tip. 
When  the  pressure  is  removed,  the  spring  forces  the  valve  back  on  its  seat  and 
the  transverse  openings  in  the  body  of  the  valve  are  closed.  This  oiler  can  easily 
be  made  at  a  machine  shop  at  small  expense.  It  has  been  in  use  at  the  High- 
land Boy  mine  since  the  starting  of  the  tramway  which  conveys  the  ore  to  the 
Tooele  smeltery  of  the  International  company,  and  has  been  found  to  work 
admirably. 

Anchoring  Wire  Ropes  (By  A.  Livingstone  Oke). — The  diagrams  shown 
in  Fig.  148  may  be  found  useful  to  illustrate  the  methods  that  may  be  adopted 
for  anchoring  wire  ropes.  In  Fig.  i  is  shown  in  section  and  plan  how  to 
secure  the  end  of  the  rope  in  soft  soil,  such  as  a  gravel  bank.  A  trench  is  dug 
in  the  form  of  a  T,  its  size  depending  on  the  load  to  be  put  on  the  rope.  With 


HOISTING  AND  TRANSPORTATION  221 

this  arrangement,  which  is  one  of  the  more  generally  employed  methods,  the 
angle  of  lead  of  the  rope  must  not  exceed  that  shown  by  the  dotted  line  at  A. 
If  a  steeper  lead  becomes  necessary  the  modification  shown  in  Fig.  2  may 
be  used,  in  which  case  the  trench  is  undercut  as  shown,  and  the  planks  inserted 
normally  to  line  of  lead.  In  Fig.  3  is  shown  a  method  of  anchorage  to  a 
post  and  is  to  be  recommended  where  some  means  of  tightening  the  rope 
has  to  be  allowed  for.  Fig.  4  shows  a  method  which  admits  any  desired 
angle  of  lead  to  the  rope;  it  consists  of  a  pit  with  its  lower  sides  undercut  to 
admit  inserting  the  cross  timber.  Fig.  5  is  an  adaptation  of  the  method 
shown  in  Fig.  3,  where  the  lead  is  horizontal.  Fig.  6  shows  a  method 
particularly  adapted  for  more  permanent  work  in  mines.  Fig.  7  is  the 
better  method,  the  end  of  the  bar  being  split  for  a  wedge  and  the  whole  calked 
with  lead;  for  vertical  upward  pull  cement  may  be  used. 


IX 


SKIPS,  CAGES,  CARS  AND  BUCKETS 

Mine  Buckets— Ore  Cars  and  Skips— Mine  Cages— Special 
Carriers— Unloaders. 

MINE  BUCKETS 

Drill-steel  Bucket. — A  bucket  for  handling  drill  steel  in  stopes  can  be 
easily  and  cheaply  made  as  follows:     The  essential  parts,  as  shown  in  Fig. 


FIG.    149. — BUCKET   FOR  DRILL   STEEL. 

149,  are  the  bucket,  handle  and  a  ring  d.  The  bucket  is  made  of  3/i6-in. 
sheet  steel,  30  in.  deep  and  10  or  12  in.  in  diameter.  The  bottom  is  made 
of  heavier  steel,  and  reinforced  by  straps  a  riveted  over  the  bottom  plate. 
The  ring  d  is  of  the  same  diameter  as  the  bucket  and  is  made  of  i/2X2-in. 

222 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


223 


iron  or  steel.  It  is  fastened  by  two  rivets  on  each  side  to  pieces  c,  4  in.  long, 
1/2X2  in.,  which  form  one  link  in  the  handle  and  hold  the  ring  in  a  horizontal 
position.  The  straps  b  are  also  1/2X2  in.,  and  are  20  in.  long.  This,  how- 
ever, should  be  regulated  by  the  length  of  steel  to  be  hoisted.  The  ring  is 
fastened  to  the  long  straps  by  a  link,  and  three  or  four  links  above  the  ring 
will  be  sufficient  to  fasten  to  the  hoisting  rope.  The  bucket  may  be  made 
light  or  heavy,  according  to  the  work  to  be  done.  A  bucket  of  this  description 
is  being  used  by  the  Vermont  Copper  Company. 

Tram  Car  for  the  Prospector  (By  Guy  C.  Stoltz). — In  the  Gowganda 
district,  Ont.,  where  a  real  tram  car  is  a  luxury  to  the  prospector,  he  has 


fBail 


FIG.    150. — BUCKET  AND   TRAM   PLATFORM. 

evolved  the  substitute  shown  in  Fig.  150.  The  half  barrel,  strengthened  by 
iron  strips,  is  fitted  with  bails  and  used  as  a  bucket.  It  is  hoisted  by  windlass 
from  the  prospect  shaft,  and  at  the  surface  is  swung  out  on  a  movable  platform 
and  detached  from  the  winding  rope.  The  platform,  3  ft.  square,  is  made 
of  2-in.  plank,  fitted  with  notched  runners,  and  rests  on  the  inverted  V  guide 
rails,  which  are  spiked  to  a  floor,  covering  the  trestle  bents.  The  windlass  men 
draw  the  bucket  of  waste  rock  to  the  dump  at  the  end  of  the  trestle  by  a  rope 
attached  to  the  ring  shown  on  the  platform.  In  summer  axle  grease  and  in 
a  freezing  temperature  water  is  applied  to  the  runners  and  guide  rails. 


224 


HANDBOOK  OF  MINING  DETAILS 


The  Mineville  Ore  Bucket. — Buckets  used  in  Mineville,  N.  Y.,  for 
hoisting  from  an  open  pit  or  a  large  winze  present  certain  advantages  over  the 
usual  cylindrical  type  in  the  manner  of  loading  and  dumping.  They  are  of 
the  stone-boat  type.  The  bucket  can  be  drawn  to  the  foot  of  the  stope  of 
ore,  where  the  low  sides  and  large  rilling  area  facilitate  the  loading  by  hand 
shovels.  Preparatory  to  hoisting,  the  chain  which  is  attached  by  U-bolt  A 
(Fig.  151)  to  the  bail  is  made  fast  to  the  lip  of  the  bucket  by  passing  the  hook 
on  the  free  end  of  the  chain  through  a  3-in.  ring  B  welded  in  the  eye  of  a  strap 
of  flat  iron  which  is  riveted  to  the  bottom  of  the  bucket.  The  hook  is  bent 
at  such  an  angle  that  after  passing  through  the  eye  it  can  be  forced  back 


FIG.    151. — IRON-ORE   BUCKET   USED    BY    PORT  HENRY    IRON    ORE   CO. 

against  the  chain  and  locked  in  this  position  by  a  slip-ring  C.  The  bucket 
after  being  locked  is  hoisted  vertically  to  the  top  of  the  pit  and  then  carried 
out  horizontally  on  the  traveling  cable  to  the  loading  tracks,  or  in  the  case 
of  a  winze  near  the  top  of  the  headframe  the  bail  is  hooked  by  an  auxiliary 
rope  and  as  the  bucket  is  lowered  it  is  carried  out  to  the  dumping  chute.  By 
knocking  the  slip-ring  with  a  shovel,  the  hook  is  released  and  the  bucket  dis- 
charges its  contents.  The  bucket  is  24  in.  deep,  4  ft.  6  1/2  in.  long  and  weighs 
noo  Ib.  The  body  is  made  of  i/2-in.  steel  plate,  with  the  corners  reinforced 
by  3X3Xi/2-in.  angle  iron. 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


225 


Joplin  Bucket  Cars. — With  a  few  exceptions,  the  hoisting  in  the  lead  and 
zinc  mines  of  southwestern  Missouri  is  done  in  buckets — "cans"  and  "tubs," 
as  they  are  called  in  the  district.  This  permits  the  use  of  narrow-gage  track, 
so  that  sharp  curves  can  be  laid  around  the  pillars  and  through  the  "  drifts,"  as 
the  openings  between  the  pillars  are  called.  Because,  as  a  rule,  the  tubs  hold 
only  about  800  lb.,  1250  Ib.  being  the  maximum  capacity,  a  light  track  can  be 
used  that  is  cheap  to  install  and  quickly  and  readily  changed.  In  fact,  in  many 
of  the  mines  the  track,  made  of  8-lb.  rails,  is  lifted  up  bodily,  ties  and  all;  the 
ties  are  usually  2-in.  planks.  This  system  is  flexible,  and  admirably  adapted  to 
the  conditions  prevailing  in  the  district.  The  hoisting  system  is  excellent,  and 
because  of  the  simplicity  of  the  hooking  and  tramming  routine  that  has  been 
evolved,  these  tubs  can  be  hoisted  at  an  average  rate  of  one  in  35  seconds  without 
great  exertion  on  the  part  of  the  men.  Indeed,  more  than  1000  tubs  have  been 
hoisted  in  one  shift  of  7  1/2  hours  by  a  single  engine,  and  with  the  hoistman 


Side  View  of  Tub  Truck  Bottom  View  of  Tub  Truck 

FIG.    152. — BUCKET   CARS   USED    IN   THE   JOPLIN   DISTRICT. 

dumping  the  tubs  himself.  At  some  of  the  mines,  cars  have  been  used  under- 
ground, but  it  is  questionable  whether  they  are  more  economical.  The  only 
advantage  of  the  car  over  the  tub  is  that  it  is  more  difficult  for  the  shovelers  to 
build  "windies"  in  them.  In  the  vernacular  of  the  district,  tubs  loaded  with 
boulders  in  such  a  way  as  to  leave  the  maximum  free  space  between  them,  are 
called  "windies." 

Many  excellent  features  are  embodied  in  the  construction  of  the  tub  cars. 
For  instance,  the  wheels  are  mounted  loosely  upon  the  axles,  and  the  axles  are 
loosely  attached  to  the  truck  by  sleeve  bearings,  so  as  to  admit  of  lateral  as  well 
as  up  and  down  movement  of  the  wheels  in  respect  to  the  truck.  This  is  an 
important  feature,  because  of  the  lightness  and  temporary  nature  of  much  of 
15 


226 


HANDBOOK  OF  MINING  DETAILS 


the  track  that  is  used  in  these  mines.  By  the  use  of  the  sleeve  attachment,  the 
four  wheels  of  the  car  stay  on  the  rails,  no  matter  how  rough  the  track  is.  It  is 
impossible  for  the  truck  to  run  on  three  wheels  at  rough  places  in  the  track 
which,  with  trucks  of  the  ordinary  type  of  axle,  is  a  common  cause  of  derail- 
ment. The  looseness  of  the  attachment  and  the  open  bearing  make  the  use  of 
oil  impossible,  so  cocoa  butter  is  used  to  lubricate  the  axle  and  the  sleeve 
bearings. 

There  are  two  types  of  bearings  used  on  these  tub  cars,  and  likewise  there  are 
two  types  of  axles.  Some  of  the  cheaper  trucks  are  equipped  with  round  axles 
and  sleeves  of  the  first  type  shown  in  Fig.  152,  but  the  round  axles,  which  are 
from  i  1/4  to  i  1/2  in.  in  diameter,  turned  down  slightly  at  the  ends,  frequently 
break  just  at  the  points  where  the  holes  are  drilled  to  receive  the  pins  that 
limit  the  side  motion  of  the  axle  in  the  sleeves.  At  one  mine,  instead  of  using 
two  pins,  a  piece  of  old  pipe  is  put  over  the  round  axle  to  form  the  shoulders 
that  limit  the  side  play,  and  this  pipe  is  fastened  to  the  axle  by  a  rivet  through 
the  axle  halfway  between  the  sleeves  where  the  bending  strain  is  least.  But 
probably  90%  of  the  axles  in  the  district  are  of  square  section,  turned 
down  for  3  in.  at  each  end  to  receive  the  wheels.  These  axles  seldom  break. 
The  truck  proper  consists  of  two  2X6-in.  pieces  of  oak  fastened  together  by 
two  crossed  iron  straps  on  the  under  side  at  the  bearings,  while  the  deck  of  the 
truck  consists  of  two  2-in.  planks,  10  to  12  in.  wide,  nailed  to  the  two  2X6-in. 
pieces.  The  gage  ranges  from  14  to  16  in.,  but  the  latter  is  coming  to  be 
regarded  as  the  standard. 

ORE  CARS  AND  SKIPS 

Wooden  Ore  Car. — A  simple  type  of  ore  car  used  by  the  Sulphur  Mining 
&  R.  R.  Co.  at  its  mine  near  Mineral,  Va.,  is  illustrated  in  Fig.  153.  The 


FIG.    153. — SULPHUR,    MINING  AND    RAILROAD    CO.'S    ORE    CAR. 

side,  end  and  bottom  boards  of  the  cars  are  of  i  i/2-in.  white  oak,  braced  with 
3/4X3-in.  wrought-iron  bars.     The  cars  are  designed  for  a  capacity  of  41  cu.  ft. 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


227 


As  the  cars  are  dumped  by  a  revolving  tipple  no  arrangement  is  provided  for 
unloading.  The  car  is  strong,  easily  constructed  and  is  to  be  commended  for 
use  at  the  mine  where  lumber  and  labor 'are  cheap.  The  wheel  base  is  24  in., 
length  of  car,  inside,  60  in.  and  outside  dimension  64  1/2  in.  The  i/4-in.  plates 
are  on  timbers  that  extend  4  in.  beyond  the  end  of  the  car  and  serve  as  a  bumper. 
A  Joplin  Car  for  Boulders  (By  Claude  T.  Rice). — In  the  mines  of  the  zinc 
and  lead  district  of  southwestern  Missouri  the  ore  is  hoisted  in  buckets,  then 
dumped  on  grizzlies  spaced  4  1/2  to  6  in.  apart,  and  the  barren  portion  of  the 
oversize  is  sorted  out  and  taken  to  the  dump.  The  headframes  are  of  the 
derrick  type  in  which  the  hoist  is  placed  at  a  height  of  50  ft.  or  more  from  the 
ground.  Therefore,  it  is'not  desirable  to  use  a  large  car  for  tramming  boulders 
as  it  would  require  a  heavy  trestle  from  the  derrick  to  the  boulder  pile.  More- 


Detail  of  Straps  H  Detail  of  Latch  E 

FIG.    154. — CAR  FOR  TRAMMING   BOULDERS,   AS   MADE  AT  JOPLIN. 

over,  because  the  life  of  most  of  the  mines  is  short,  a  cheap  construction  is 
desirable.  As  will  be  seen  in  Fig.  154,  the  car  is  an  end  dump  one  having  a 
turntable  deck  carried  on  a  wooden  truck.  The  wooden  box  of  the  car,  which 
is  open  at  the  front  end,  is  hinged  to  the  turntable.  The  edges  of  the  side  boards 
are  bound  with  strap  iron  and  are  reinforced  by  the  bands  H,  passing  under 
the  body  of  the  car  and  up  the  sides.  The  box  is  prevented  from  dumping  by 
a  simple  hook  on  one  side  of  the  box.  The  loaded  car  holds  about  1000  Ib. 
of  boulders. 

Tram  Car  for  Stope  Filling. — The  accompanying  drawing,  Fig.  155, 
shows  the  details  of  construction  of  cars  used  in  the  stopes  at  the  Copper 
Range  mines  at  Painesdale,  Mich.,  where  a  waste-filling  system  of  mining  is 
used.  These  cars  hold  a  ton  of  waste  and  have  the  long,  low  bodies  charac- 
teristic of  copper-country  mine  cars.  The  long  body  is  of  advantage  in 


228 


HANDBOOK  OF  MINING  DETAILS 


spreading  the  filling,  as  it  allows  the  filling  to  be  dumped  somewhat  farther  to 
one  side  than  could  be  done  with  a  car  with  a  short  body.  The  height  that  the 
shoveler  has  to  lift  the  ore  is  also  reduced.  The  body  of  the  car  is  fastened 
to  the  truck  by  a  hinge  carried  on  a  turntable  on  the  truck  frame.  The  wooden 
truck  is  now  being  made  of  fir.  Some  of  these  cars  are  equipped  with 
Peleter  bearings  as  are  cars  on  the  main  levels,  while  others  have  ordinary 
bearings.  The  bolt  passing  through  the  hinge  can  be  taken  out  easily 
when  the  car  is  to  be  raised  into  or  lowered  out  of  the  stope,  and  the  body 
dismounted  for  handling  it  through  the  chutes. 

Tram  Car  with  Automatic  Door. — A  tram  car  with  an  automatically 
opening  and  closing  door  has  been  constructed  under  the  direction  of  A.  J. 


x  %-in.  Angle 


Strap          .  /Strap 

.    /.       .    pS^    .  -      -       -        -      -      -    pSb   -       -  -      -       -        -      -  p 


Strap 


%  x  2-in.  Strar 


between  Cross-bars 
of  Upper  Ring  and 

3;   Top  of  Maple  Truck 

O 


FIG.    155. — TRIMOUNTAIN   CAR   FOR   STOPE    FILLING. 

Cummings,  superintendent  of  the  Cheever  Iron  Ore  Co.,  operating  near  Mine- 
ville,  N.  Y.  Previous  to  the  use  of  a  car  rigged  with  a  door  in  this  manner, 
a  door  was  used  which  required  the  tram  man  to  open  it  before  entering  the 
tipple.  If  the  door  would  not  open,  as  was  often  the  case,  the  loaded  car 
had  such  momentum  that  it  would  enter  the  tipple  and  turn  to  the  dumping 
angle,  thus  making  it  difficult  to  open  the  door.  Trips  were  attached  to  the 
tipple  to  open  the  door,  but  nothing  could  be  rigged  conveniently  to  close  the 
doors  mechanically.  Open-end  cars,  designed  by  Koppel,  were  used,  but  these 
required  extra  care  in  loading  large  lumps  of  ore  at  the  open  end  to  prevent  the 
fine  ore  from  rolling  out  on  the  tram  tracks.  It  was  necessary  to  have  the  car 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


229 


fitted  with  a  door  in  order  to  load  to  full  capacity.  The  Koppel  cars  were 
then  rigged  with  the  automatically  operated  doors  and  these  have  been  entirely 
satisfactory.  Iron  plates  are  tapped  and  riveted  near  the  top  and  center  of 
the  sides  of  the  car  and  to  these  lugs  are  screwed.  Two  arms  of  flat  iron  are 
attached  to  the  lugs  and  extend  out  to  the  front  end  where  they  are  split  and 
riveted  to  the  door.  On  the  horizontal  center  line  of  the  door  a  strip  of  flat 
iron  is  riveted  and  the  ends  are  swedged  to  i-in.  diameter  to  receive  rollers 
which  extend  beyond  the  body  of  the  car.  The  door  is  kept  in  position  by 
resting  on  two  supports  formed  by  splitting  the  flange  of  the  channels  at  the 
end  of  the  car  and  bending  them  to  the  proper  angle.  As  the  car  enters  the 
tipple  and  dumps,  the  rollers  carrying  the  door  are  guided  in  a  horizontal 
course  by  riding  on  4X5~in.  maple  pieces  bolted  to  each  side  of  the  tipple 
frame. 

Side  Dump  Mine  Car  (By  Claude  T.  Rice) . — Where  ore  is  hauled  in  trains, 
the  cars  must  be  of  the  side-dump  type  to  be  economical.  Side-dump  cars  are 
also  better  adapted  to  dumping  into  raises  at  the  side  of  the  tracks,  or  into 
the  skip  pockets  in  a  shaft  station  or  into  the  bins  at  the  surface.  The  lifting 


Trunnion -EH 


ncuRm         j 


4"I-beam 


\®£~-  —  Cast  Steel  Truck  -  :=\Q) 


FIG.    156.  -  SIDE-DUMP   CAR   USED  AT   NORTH   STAR   MINE,    GRASS   VALLEY,    CALIF. 

of  the  car  and  its  load  a  sufficient  height  to  raise  it  out  of  the  "keeps"  and 
the  swinging  of  the  whole  load  around  so  as  to  dump  the  car  over  the  side  is 
wasted  energy. 

Side-dump  cars  have  been  in  use  at  the  North  Star  mines  at  Grass  Valley, 
Calif.,  for  several  years,  the  first  having  been  designed  by  Gerald  Sherman, 
who  also  introduced  them  at  the  Copper  Queen  mines  at  Bisbee,  Ariz.  Fig. 
156  illustrates  the  details  in  the  construction  of  the  cars  in  use  underground 
at  the  North  Star  mines.  Roller  bearings  are  used  on  the  latest  cars  and  the 
wheel  base  is  only  16  in.,  on  account  of  the  sharp  turns  in  the  drifts.  The  car 
has  a  capacity  of  20  cu.  ft.  and  holds,  as  loaded  at  the  North  Star  mine,  about 
1800  Ib.  The  cars  weigh  750  lb.,  are  easily  made  and  cost  $40  each.  The 


230 


HANDBOOK  OF  MINING  DETAILS 


frame  of  the  car  consists  of  two  cast-steel  end  supports  riveted  to  two  4-in. 
I-beams  by  two  rows  of  rivets  on  each  side.  The  trunnion  is  also  made  of 
cast  steel  and  is  riveted  to  each  end  of  the  car  body.  The  car  is  reinforced  by 
three  i-in.  angle  irons  on  each  side.  No  catch  is  necessary  to  prevent  the  car 
from  upsetting  while  being  hauled  by  a  mule  or  pushed  by  a  man,  but  were 
these  cars  to  be  made  up  into  trains  to  be  hauled  by  electric  motors,  a  catch 
would  have  to  be  put  on  them  to  keep  the  car  from  turning  over  because  of  the 
greater  speed  at  which  curves  are  taken. 

Cradle  for  Dumping  Mine  Cars. — At  the  Copper  Range  mines  in  Michigan 
the  bodies  of  the  mine  cars  are  fastened  tightly  to  the  trucks  so  that  cradles 


FIG.    157. — MINE-CAR  DUMPING   CRADLE. 

must  be  used  to  dump  them  at  the  shaft.  In  dumping  on  a  level,  as  when 
filling  a  stope,  the  rails  at  the  edge  of  the  raise  coming  up  from  the  stope  below 
are  bent  down  and  then  turned  up  into  a  hook  to  catch  the  wheels.  In  this 
way  the  body  is  allowed  to  drop  enough  so  that  the  rock  will  slide  out  of  the  car. 
The  details  of  the  cradles  which  are  made  to  template  are  shown  in  Fig.  157. 


SKIPS,  CAGES,  CARS  AND  BUCKETS  231 

Two  strap-irons  protect  the  front  of  the  cradle  timbers  where  they  hit  the 
floor  of  th'e  station  when  the  cars  are  being  dumped.  The  axle  on  which  the 
cradle  turns  is  provided  with  collars  to  limit  the  side  play  of  the  cradle,  while 
the  axle  is  carried  in  strap  bearings  on  two  6X6-in.  timbers  that  extend  back 
under  the  ties  of  the  track  so  that  they  are  securely  anchored  in  place,  and 
through  them  the  cradle  itself.  Thimbles  protect  the  cradle  timbers  from  wear 
by  the  axle,  and  the  rails  on  the  cradle  are  turned  up  at  the  end  so  that  the  car 
cannot  be  pushed  off  into  the  shaft.  In  dumping,  the  front  of  the  car  either 
strikes  the  station  floor  or  else  the  top  of  the  skip  if  that  happens  to  be  raised 
a  little  too  high,  so  that  owing  to  its  long  body,  the  car  cannot  go  over  far 
enough  to  overbalance  itself.  Such  would  not  be  the  case  if  the  car  had  a 
short  body  like  most  mine  cars  used  in  the  West.  In  order  to  prevent  accidents 
from  men  stepping  on  the  cradles,  the  cradles,  when  installed,  are  always 
tested,  even  though  made  alike  and  according  to  template,  and  a  cradle  must 
be  able  to  hold  the  weight  of  a  man  standing  on  the  far  edge  without  dumping. 
Otherwise  a  cradle  might  sometime  throw  a  man  into  the  shaft  when  he 
happened  to  step  on  it.  The  car  rests  on  the  cradle  in  such  a  way  that  a  little  lift 
is  necessary  to  dump  it. 

Calumet  &  Hecla  Ore  Cars.— The  Calumet  &  Hecla  is  one  of  the  few 
companies  in  the  Lake  Superior  copper  district,  that  uses  ore  cars  having 
doors.  At  the  other  mines  the  cars  are  open  at  the  front  end  and  closed  at  the 
back.  The  men  pile  boulders  at  the  front  to  hold  in  the  finer  dirt  and  this 
is  a  waste  of  time. 

All  the  Lake  Superior  cars  are  built  with  the  body  resting  directly  on  the 
axles  so  as  to  allow  them  to  be  made  with  the  sides  as  near  the  ground  as  possible. 
The  usual  capacity  is  2  1/2  tons,  hence  the  cars  are  made  with  long  bodies, 
especially  where  the  tracks  have  the  usual  3-ft.  4-in.  gage;  a  4-ft.  gage  is  used 
at  the  Calumet  &  Hecla  mines.  Owing  to  the  wide  gage  the  cars  have  to 
have  a  short  wheel-base  compared  to  their  length  so  as  to  allow  them  to  make 
the  turns  without  cramping.  The  front  axle  is  bolted  directly  to  the  body  of 
the  car  while  the  rear  axle  is  attached  to  the  forward  axle  by  two  distance 
straps  that  slip  loosely  over  the  axles.  The  front  hole  in  the  strap  is  made 
circular  to  allow  the  axle  to  turn  in  it  when  the  body  of  the  car  is  being  raised 
to  dump,  while  the  back  hole  is  made  square  to  go  over  the  square  part  of  the 
back  axle.  In  the  center  of  the  back  axle  there  is  a  lug  that  fits  into  a  hole  in 
the  bottom  of  the  body  so  as  to  prevent  side  swing  while  the  car  is  being  pushed 
along  the  track. 

The  front  door  of  the  car  is  made  to  swing  up  and  is  carried  from  a  cross 
rod  in  the  ends  of  two  horns  that  extend  above  the  car  so  as  to  afford  plenty  of 
space  for  rolling  in  boulders.  The  door  at  the  other  end  of  the  car  is  made 
to  drop  down  so  as  to  allow  perfect  freedom  in  handling  the  boulders.  This 
door  only  comes  two-thirds  the  way  to  the  top.  As  the  rear  door  is  sometimes 


232 


HANDBOOK  OF  MINING  DETAILS 


used  as  an  apron  to  aid  in  loading  boulders,  it  is  secured  to  the  car  by  four 
straps  instead  of  three,  as  in  the  case  of  the  front  door. 

These  doors  are  locked  by  a  rather  ingenious  device.  To  the  doors  are 
fastened  two  bolts  with  nuts  on  them,  a  link  intervening  so  as  to  give  flexibility, 
as  shown  in  Fig.  158.  By  means  of  the  nut,  which  is  a  tight  fit  on  the  locking 
rods,  the  length  of  the  locking  pin  is  adjusted  so  as  to  give  the  proper  tension 
when  the  bolt  is  down  in  the  keeps.  The  keeps  into  which  the  locking  bolts 
drop  are  made  of  cast  iron  and  are  bolted  to  the  sides  of  the  car.  The  back 


Front  Door 


itching 
Bolt 


> 

Keep 

£51 

Keep                  ^Wheel  Guards^ 

&3i         <^^>    <^^ 

*          <^ 

Front  Axle  Attached 
Side  Elevation  of  Car  Body. 


Fits  on  Square 
Section  of  Axle 


°f  Latchlng  Bolt  and  Kee*> 


.Edge  of  Carbody 

j    Distance  Strap 
Square  Section 


Loose  Fit  on  Round 
Section  of  Axle 


Rear  Axle 
Front  Axle  not  attached 
attached  to  to  Body 

Body 


Axle  Turned  Round 
to  here 


_Gag.e 

3-ft.4-in.  or  4-ft. 


Edge  of  Carbody 


Side  Elevation  of  Distance  Strap.  Plan  of  Truck. 

FIG.    158. — TWO-DOOR   CAR   FOR   TRAMMING    BOULDERS. 

end  of  these  keeps  is  slightly  rounded  so  that  the  bolt  is  tightened  as  it  is  shoved 
down  in  them,  while  the  bottom  part  is  straight  and  designed  to  be  perpen- 
dicular to  the  locking  bolt  when  it  is  down  in  the  keeps.  A  slight  knock  on  the 
end  of  the  locking  bolt  loosens  it  so  as  to  open  the  gate,  but  the  bind  against 
the  keep  is  sufficient  so  that  no  jar  can  loosen  the  door  while  the  car  is  being 
trammed.  The  accompanying  sketch  shows  the  keep  in  detail.  To  prevent 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


233 


234 


HANDBOOK  OF  MINING  DETAILS 


fine  rock  from  dropping  upon  the  axles,  wheel  guards  made  of  2-in.  angle  iron 
are  bolted  to  the  side  of  the  cars.  The  wheels  are  loose  on  the  axles  being  held 
on  by  keys. 

Coeur  d'Alene  Mine  Car. — In  Fig.  159  is  shown  a  type  of  mine  car  used 
in  the  Cceur  d'Alene  district  of  Idaho.     This  particular  car  is  used  at  the 


|<- ~~6ac{e4Ll"     -->( 

FIG.  1 60. — MAN  CAR  FOR  AN  INCLINED  SHAFT. 

Morning  mine,  of  the  Federal  Mining  &  Smelting  Co.,  at  Mullan,  and  is 
similar  to  the  Bunker  Hill  &  Sullivan  cars.  The  capacity  of  the  car  is  68.3 
cu.  ft.,  and  it  is  used  in  the  long  adit  tunnels  in  which  ore  from  the  mine  is 
conveyed  to  the  mill  or  shipping  point.  The  advantages  of  this  type  of  car 
are  in  its  strength  and  durability,  with  which  is  combined  simple  structural 


SKIPS,  CAGES,  CARS  AND  BUCKETS  235 

details  and  rapidity  of  operation.  The  body  of  the  car  is  made  of  i/4-in. 
steel  plate,  reinforced  with  angle  iron.  The  patterns  of  the  plates  forming 
the  body  of  the  car  are  shown  in  the  drawing.  This  body,  with  sloping  bottoms, 
as  shown,  rests  in  a  cradle  made  of  4X  8-in.  wooden  beams  set  on  end,  and  sup- 
ported from  the  axles.  The  car  axles  are  heavy,  being  3  1/2  in.  in  diameter, 
turned  to  2  3/4  in.  at  the  bearings.  The  wheels  are  20  in.  in  diameter,  running 
on  a  24-in.  track.  The  overall  dimensions  of  the  car  are:  Width,  51  1/4  in.; 
height,  55  5/16  in.;  length,  90  1/2  in.  The  bottom  of  the  body  of  the  car 
consists  of  two  sections  of  steel  plate  hinged  along  the  sides  of  the  sloping 
bottom  of  the  body.  Each  flap  is  weighted  along  its  center  with  i6-lb.  rails 
and  supported  by  chains  from  a  winding  shaft  across  the  body  of  the  car. 
The  car  is  dumped  by  simply  loosening  the  ratchet  gear  controlling  this  winding 
shaft.  The  weight  of  the  ore  and  the  rails  on  the  bottom  doors  serve  to  swing 
them  open.  A  few  turns  of  the  winding  shaft  suffices  to  close  the  car  again. 
The  handle  used  for  this  purpose  is  kept  at  the  point  at  which  the  cars  are 
to  be  dumped.  One  man  dumps  all  the  cars  of  a  train.  The  winding  axle 
terminates  at  one  end  in  a  ratchet  wheel.  A  dog  engages  this  ratchet  and  the 
dog  is  locked  in  place  by  a  keeper.  The  dog  and  keeper  are  each  pivoted  to 
the  body  of  the  car.  To  dump  the  car,  the  keeper  is  knocked  up  so  as  to 
disengage  the  dog  from  the  ratchet  wheel.  The  details  of  this  dump  mechanism 
are  shown  in  the  drawing.  One  man  is  able  to  dump  15  cars  in  about  3  minutes. 

Copper  Range  Man  Car. — The  car  used  for  lowering  and  raising  men 
at  the  mines  of  the  Copper  Range  company,  in  the  Michigan  copper  district, 
is  shown  in  Fig.  160.  It  is  designed  for  use  in  a  shaft  sunk  at  an  inclination 
of  70°  from  the  horizontal  and  is  a  two-deck  car,  there  being  room  for  13  men 
on  each  deck.  The  sides  of  the  car  are  covered  with  i/2-in.  mesh  wire  cloth, 
and  the  front  is  closed  by  gates,  one  for  each  deck,  that  slide  in  channel  guides, 
a  set  of  which  is  provided  for  each  gate  at  the  front  of  the  car.  The  gates  may 
be  locked  in  position  above  the  men's  heads,  or  waist  high  by  throwing  the 
lever  which  pushes  two  rods  out  through  holes  in  the  channels  provided  for  the 
purpose.  The  flooring  of  the  upper  deck  is  held  in  place  by  two  pairs  of 
channels,  between  which  it  slides,  so  that  it  may  be  removed  when  timbeis 
are  to  be  lowered.  The  lower  parts  of  the  gate  guides  are  also  cut  away,  so 
that  the  gates  can  readily  be  removed  when  the  car  is  to  be  used  for  this  purpose, 
and  a  bolt  that  hooks  into  eyes  on  each  side  of  the  car  just  below  the  upper  deck, 
and  which  prevents  spreading  or  bulging  at  the  sides,  can  likewise  be  removed 
to  make  room  for  the  timbers.  The  hood  at  the  top  of  the  car  is  hinged  so 
it  may  be  laid  back  when  3o-ft.  rails  are  to  be  lowered.  In  order  to  prevent 
accidents  that  might  occur  if  one  of  the  wheels  should  break  while  the  skip 
is  in  motion,  two  pairs  of  skids  are  attached  to  the  under  part  of  the  body,  which, 
in  the  case  of  such  breakage,  would  support  the  car  upon  the  rail. 

Copper  Range  Ore  Skip. — The  6-ton  skips  used  in  the  Copper  Range 
mines  in  the  Lake  Superior  copper  country,  present  several  novel  details  of 


236 


HANDBOOK  OF  MINING  DETAILS 


construction,  especially  in  the  manner  of  attaching  the  draft  lugs  to  the  body 
of  the  skip,  the  system  of  oiling  the  wheels,  and  attaching  the  collars  to  the 
different  lugs,  bails  and  wheels.  All  hubs  on  which  collars  are  used,  are  drilled 
for  a  split  pin  which  holds  the  collars  in  place.  The  hubs  are  also  cut  with 
slots  at  45°  that  receive  the  rivet  pins  of  the  collar. 

In  the  drawings  of  the  Champion  skip  given  in  Fig.  161  the  details  of  the 
draft  lug  and  the  collar  used  with  it  are  shown.     Projecting  from  the  inside 


*\  II 


Detail 'of  Bridle 




J  - 

-J    ~               '     '                                                                                     •  lqP 

o 
o 

0 

b 

'o 

,              "1                                                                                                                  ,V£>     Ij3j 

9"p;»v*fa        Detail  of  Draff  Luq 
g  Pm Hole  and  Collar      y 


Side  Elevation 


Elevation  of  Bottom 


FIG.    l6l. — DETAILS    OF   THE    SKIP   USED   AT   THE    CHAMPION   MINE. 

surface  of  the  collar  and  at  90°  from  the  hole  drilled  to  receive  the  split  pin, 
are  two  pins  riveted  into  holes  in  the  collar.  In  assembling  the  collar  on  the 
lug,  the  pins  are  slid  into  the  notches  to  the  bottom  and  then  the  collar  is 
turned  through  an  arc  of  45°.  This  causes  the  pins  to  enter  the  grooves  and 
when  they  are  against  the  ends  of  the  two  grooves,  the  holes  for  the  split  pins 
in  the -collar  are  in  line  with  the  holes  in  the  axle  and  the  split  pins  may  be  forced 
through.  In  this  way  the  collar  is  held  at  four  points  instead  of  at  two,  and 
thus  held  securely.  All  of  the  other  collars  are  attached  in  a  similar  way. 
The  body  of  the  skip  is  reinforced  at  the  lugs  by  an  extra  plate.  The 
bridle  strap  is  bent  so  as  to  clear  the  front  wheel.  In  order  to  keep  the  skip 


SKIPS,  CAGES,  CARS  AND  BUCKETS  237 

as  low  on  the  rails  as  possible,  the  wheels  are  mounted  on  hubs  riveted  to 
the  sides  instead  of  on  axles.  At  the  bottom  there  are  two  reinforcing  straps, 
while  on  the  under  side  and  at  the  front  end  there  are  two  straps  that  take 
the  wear  that  comes  on  the  skip's  bottom  when  going  over  the  roller  of  the 
dumps.  By  attaching  the  draft  pins  by  lugs  riveted  to  the  body  or  the  inside 
of  the  skip,  the  lugs  are  fastened  much  more  securely  than  if  riveted  to  the 
outside,  as  is  the  usual  way. 

The  method  of  oiling  the  wheels  is  shown  in  the  drawing  of  the  axle.  The 
ends  are  hollow  and  three  holes  in  the  walls  let  the  grease  out  to  the  wheels. 
The  wheels  are  made  with  a  receptacle  in  them  that  also  becomes  filled  with 
grease  and  acts  as  a  reservoir,  there  being  four  holes  drilled  through  the  brass 
bushing  to  connect  with  the  reservoir.  These  grease  cavities  are  closed  by  a 
screw  plug  that  cannot  be  taken  out  without  removing  the  collar  from  the  axle. 
The  grease  is  shot  into  the  wheels  by  a  plunger  gun  that  screws  into  the  axle. 
Formerly  when  the  wheels  of  the  skip  were  filled  with  oil  and  the  oiling  of  the 
axles  was  done  by  oil  feeding  down  on  them  from  these  reservoirs,  the  wheels 
had  to  be  filled  four  times  per  day,  while  the  grease  well  has  to  be  filled  only 
once  in  48  hours. 

The  rope  is  attached  around  a  thimble.  This  thimble  is  now  made  solid 
instead  of  having  its  sides  cut  away  and  only  reinforcing  ribs  going  across,  as 
they  were  formerly  made;  that  construction  proved  to  be  too  weak.  The 
manner  of  attaching  the  lugs  and  collars,  as  well  as  the  methods  of  oiling  with- 
out the  necessity  of  taking  off  the  collars,  was  devised  by  W.  J.  Richards,  the 
master  mechanic  of  the  Copper  Range  Consolidated  Co. 

The  Franklin  lo-ton  Skip. — There  is  but  one  hoisting  compartment  in 
the  No.  i  amygdaloid  shaft  of  the  Franklin  mine  near  Houghton,  Mich.,  so 
in  order  to  raise  the  desired  tonnage,  a  skip  of  223  cu.  ft.  or  10  1/2  tons'  capacity 
is  required.  This  skip  is  by  far  the  largest  in  the  Lake  Superior  copper 
country.  The  front  wheels  of  the  skip,  as  shown  in  Fig.  162  are  carried  by 
bracket  axles  which  are  bolted  to  the  body  of  the  skip,  the  clearance  between 
the  inside  face  of  a  wheel  and  the  body  being  about  i  in.  A  reinforcing  plate 
through  which  these  bracket-axle  bolts  pass  stiffens  the  body  of  the  skip  at 
that  point.  The  body  is  also  reinforced  at  the  draft  lugs.  Because  of  the 
small  clearance  of  the  front  wheels  it  is  necessary  to  bend  the  bridle  strap 
so  that  it  will  clear  the  wheels.  At  that  part  of  the  bottom  of  the  skip  on  which 
the  ore  from  the  loading  pocket  falls  when  the  skip  is  being  filled  a  wooden 
lining  is  used  which  extends  a  little  below  the  reinforcing  plate  for  the  bracket 
axles.  The  rest  of  the  bottom  is  reinforced  by  steel  channels,  every  other  one 
of  which  is  inverted;  all  are  riveted  together  as  shown  in  the  section  A«-A  in 
the  illustration.  The  skip  is  equipped  with  skids  that  will  take  the  weight  in 
case  a  wheel  breaks,  and  also  with  guide  shoes  that  run  over  a  concrete  stringer 
in  the  shaft  and  which  will  guide  the  skip  in  the  event  of  its  jumping  from  the 
rails.  The  rear  axle  is  pivoted  and  is  carried  in  sleeves  which  allow  a  play 


238 


HANDBOOK  OF  MINING  DETAILS 


of  i  1/2  in.  The  front  and  back  wheels  are  alike  and  are  made  of  manganese 
steel,  while  the  increase  in  the  tread  necessary  on  the  rear  wheels  for  dumping 
the  skip  is  obtained  by  a  separate  hub  that  is  carried  outside  the  main  wheels 
and  on  the  same  axle.  This  hub  is  a  cheap  steel  casting  as  it  does  not  have  to 
take  much  wear.  At  the  rear  are  lugs  for  attaching  below  the  skip  a  truck 
for  lowering  timbers.  The  skip  weighs  about  61/2  tons.  The  skip  track 
is  5-ft.  gage  and  is  made  of  8o-lb.  rails  carried  on  concrete  stringers  of  the 
Mohawk  type. 


I 

i 

1 

1 

.a 

1 

• 

i'i    C 

b 

1 

.S 

Top  %-in.  Plate 

SJ 

1 

0 

'"* 

l!  !    -*• 

1  I 

1  • 

0 

i'i" 

1 

5  s  5  i  Vi-in.  L 

6  i  G  x  }£-in.  L 


-11- ft.  6-in.— 


iJi 


?L_* 


-In.  Plank 
Filler 


15-ft.  yA-irr. 


5-ft. 


-A     •$        fil  1-in.BarFni! 

'V''0    _iPE    /Lining  and  Bolts 


12  x  1,^-in.  Plate 

Section  A-A 


FIG.    162. — THE    10-TON   SKIP   FOR   THE   FRANKLIN    MINE. 


Skip  and  Dump  Plate  for  Vertical  Shaft  (By  Lee  L.  Wilcox).— A  modi- 
fication of  the  De  Beer's  type  of  skip  for  a  vertical  shaft,  which  is 
an  improvement  over  the  old  type,  is  shown  in  Fig.  163.  The  top  of  the  old 
type  of  De  Beer's  skip  was  square  and  trouble  was  experienced  from  ore 
falling  back  into  the  shaft.  This  not  only  gave  the  shaft  an  untidy  appear- 
ance, but  in  a  few  instances  the  men  working  near  the  shaft  were  seriously 
injured  by  falling  pieces  of  ore.  Attempts  were  made  to  improve  the  skip;  in 
one  instance  a  lip  was  riveted  to  the  bottom  plate;  in  another  a  filling  piece 
was  attached  to  the  dump  plate,  thus  throwing  the  lip  up  farther  from  the 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


239 


edge  of  the  shaft.  These  changes  proved  to  be  only  partially  successful  in 
stopping  the  ore  from  falling  back  down  the  shaft,  but  they  introduced  other 
faults  which  were  nearly  as  bad.  The  lip  would  spread  the  discharge  of  ore  so 
that  it  would  lie  on  the  dump  angles,  causing  the  skip  to  stick  as  it  descended ; 
and  the  filling  piece  decreased  the  inclination  of  the  skip  when  dumped  so 
that  it  did  not  clear  itself  readily. 

When  the  new  Pettit  headframe  was  built  it  was  decided  to  make  some 
changes  in  the  design  of  the  skip.  It  was  made  longer  in  proportion  to  the  base 
than  is  customary;  the  dimensions  being,  base  3X4  ft.  and  length  6  ft.  on  one 
side  and  5  ft.  on  the  other.  The  base  dimensions  are  unusual,  because  of 
local  conditions.  Under  ordinary  conditions  it  would  have  been  made  nearly 


~ 


Amide 


-I 


A 


®         'Coffer 


0|0  0  0 


FIG.    163. — SKIP  AND   DUMP   PLATE   USED    IN  A   MINNESOTA   IRON   MINE. 


square.  The  additional  length,  however,  throws  the  lip  considerably  farther 
away  from  the  shaft  and  all  the  ore  is  discharged  well  back  from  the  edge  of 
the  shaft.  By  incorporating  the  extended  lip  in  the  body  of  the  skip  itself,  as 
shown  in  the  illustration,  the  trouble  caused  by  the  ore  gathering  on  the  dump 
plates  was  entirely  overcome.  The  new  skip  was  satisfactory  from  the  start. 
A  few  changes  were  made  in  the  dump  plates  which  are  worthy  of  mention. 
The  dump  angles  were  shod  with  a  3/8-in.  strap;  as  this  strap  is  worn  it  can 
readily  be  replaced  without  removing  the  dump  angle  itself,  thus  making  the 
repairs  much  easier  and  simpler.  The  plate  was  reinforced  behind  the  dump 
roller  by  a  channel.  This  prevented  the  bending  of  the  plate  at  this  point 
which  on  the  larger  skips  is  troublesome. 


240 


HANDBOOK  OF  MINING  DETAILS 


Automatic  Skip  for  Inclined  Shafts.— In  Fig.  164  are  shown  the  details 
of  a  48-011.  ft.,  open-top  skip  used  by  the  Salt  Lake  Copper  Co.  at  its  mine  at 
Tecoma,  Nev.,  in  a  shaft  inclined  at  a  low  angle  from  the  horizontal.  The 
design  presents  several  novel  features,  such  as  a  curved  bottom  at  the  front  for 
directing  the  ore  when  the  skip  is  in  discharging  position  and  attachment  of 
the  bail  at  the  lower  end  or  back  of  the  body  of  the  skip. 


l'V1(;    Turu  ^  ^^  6,  v  . .  _.,_ 

^  Beariug  Ck-  ^x     ;< 32— Gage- 


Side  Elevation  Rear  Elevation 

FIG.    164. — A   SKIP  FOR  FLAT-DIPPING   SHAFT. 

Dumping  Skip  for  Winze  (By  K.  Baumgarten).—  The  automatic-dumping 
skip  shown  in  Fig.  165  was  installed  by  the  Black  Mountain  Mining  Co.  in  the 
vertical  winze  in  the  Cerro  Prieto  mine,  40  miles  southeast  of  Magdalena, 
Sonora,  Mex.  The  skip  was  designed  for  the  purposes  of  sinking.  The  total 
length  of  the  shoes  was  20  ft.,  which  admitted  of  lowering  the  bucket  16  ft.  below 
the  guides.  The  hoisting  compartments  were  4  ft.  6  in.  by  5  ft.  in  the  clear; 
the  guides  were  5  i/2-in.  surfaced  Oregon  pine.  A  i-ton  skip  was  small 
for  the  size  of  compartment,  which  was  larger  than  usual ;  the  problem  was 
to  arrange  a  bucket  of  convenient  height  for  shoveling  and  at  the  same  time  to 
provide  sufficient  height,  such  that  when  the  bucket  was  turning  over  in  the 
dumping  guides,  it  would  not  begin  to  empty  its  load  until  the  lip  was  clear  of 
the  edge  of  the  winze.  The  capacity  of  the  bucket  was  23.5  cu.  ft.  or  about  i.i 
tons.  The  shipping  weight  was  1732  Ib.  After  arrival  at  the  mine,  the  springs 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


241 


were  added,  the  "fingers"  taken  off  and  increased  to  12  in.  length,  and  a  false 
bottom  of  2 -in.  plank  put  in,  thus  increasing  the  weight  by  about  60  Ib. — a 
total  of  about  1800  Ib.  The  hoisting  equipment  was  a  5o-h.p.  three-phase 
induction  motor,  2 20  volts,  geared  to  a  drum  carrying  about  500  ft.  of  3/4-in. 
wire  rope.  The  load  designed  for  this  set  was  3  500  Ib.  but  the  hoist  was  operated 
to  a  depth  of  400  ft.  under  a  load  of  about  4000  Ib.,  or,  roughly,  15% 
overload,  exclusive  of  rope  weight.  The  cost  of  the  skip  was  $195,  to  which 
may  be  added  $18  for  freight  and  $3  for  duty,  a  total  of  $216  at  the  mine.  No 
originality  is  claimed  for  the  design,  except  that  the  wearing  plates  within  the 


.Bucket, 

Side  »nd  End  Plates     I     . 
~ 


£l'       Front 


Elevation.       Section 


FIG.    165. — AUTOMATIC   DUMPING   SKIP   FOR   WINZE. 


shoes  are  omitted,  and  to  which  may  be  attributed  the  smooth  running,  as 
there  are  no  projections  between  the  shoes  and  the  guides.  In  six  months' 
operation  no  repairs  were  necessary.  The  dumping  guides  were  made  at  the 
mine,  but  proved  to  cost  only  slightly  less  than  the  skip.  It  would  have  been 
cheaper  to  have  had  them  made  at  an  outside  machine  shop,  where  the  equip- 
ment for  such  work  was  at  hand. 
16 


242 


HANDBOOK  OF  MINING  DETAILS 


A  Timber  Skip. — At  the  South  Eureka  mine,  near  Sutter  creek,  Calif.,  a 
special  skip  is  used  for  lowering  timbers.  The  shaft  is  inclined  at  angles  varying 
up  to  about  70°.  The  timber  skip  is  hung  below  the  rock  skip  from  a  ring  on  the 
bottom  of  the  latter.  It  is  made  from  an  old  skip  by  taking  out  the  top  plate  and 
using  an  extra  long  bail,  hung  from  the  axles  of  the  front  wheels.  By  having 
the  top  of  the  skip  open,  timbers  can  be  taken  out  by  simply  swinging  them  down, 
thus  obviating  the  necessity  of  raising  and  lowering  the  skip  for  jacking.  The 
extra  length  of  bail  enables  long  timbers  to  be  handled. 

Counterbalance  for  Skips. — The  counterweight  used  at  one  of  the  iron 
mines  of  the  Cleveland- Cliffs  Co.,  at  Ishpeming,  Mich.,  consists  simply  of  one 
8-ft.  section  of  i4-in.  cast-iron  pipe  with  flanges,  mounted  in  a  frame  made  of 
plate  and  angle  iron.  The  two  side  pieces  are  i/2X  16  in.X  10  ft.,  the  upper 
and  lower  ends  being  fastened  together  with  iXio-in.  plates.  The  runners 
are  made  of  3X  4-in.  angle  iron  spaced  9  in.  apart.  These  run  on  8-in.  wooden 
guides  in  the  shaft.  The  runners  are  also  lined  with  i/4-in.  plates  both  on 
the  angle  iron  and  on  the  i/i6-in.  side  plate.  This  lining  is  easily  removed  in 
case  of  excessive  wear  and  repairs  can  be  easily  made.  A  wooden  block  is  placed 
in  the  bottom  to  act  as  a  cushion  and  also  add  to  the  strength.  The  cast-iron 


itf'u- 


Bolt 


Hinge\^A-3"x3"  "    ^A-  3  Dia. 

FIG.    l66. — IMPROVED    SKIP  AT  ADAMS    IRON   MINE. 

pipe  being  hollow  gives  ample  room  to  add  any  amount  of  scrap  iron  in  order  to 
give  it  the  desired  weight.  Another  type  of  counterbalance  used  by  the  same 
company  consists  of  a  piece  of  solid  steel  shafting  about  10  in.  in  diameter 
which  runs  inside  of  a  i2-in.  pipe.  The  pipe  thus  takes  place  of  a  guide.  Other 
counterbalances  used  at  various  mines  consist  of  a  steel  frame  work  in 
which  large  pieces  of  cast  iron  are  mounted  and  may  be  removed  or  added  to, 
as  desired,  in  the  same  manner  as  on  elevators  in  buildings. 

Skip  Improvements. — The  new  skips  that  are  being  made  for  the  Adams 
mine,  near  Virginia,  Minn.,  are  equipped  with  3 /4-in.  compression  springs 


SKIPS,  CAGES,  CARS  AND  BUCKETS  243 

beneath  the  crosshead  to  lessen  the  shock  on  the  cable  when  starting  to  lift  the 
skip  full  of  ore.  The  use  of  springs  on  skips  is  not  common  although  they  have 
been  used  on  cages.  In  the  old  skips  two  3X3-in.  iron  bars  were  used  under 
the  skip  to  support  the  load.  The  skip  is  hinged  to  o'ne  of  these  bars  for 
dumping  purposes,  and  when  vertical  simply  rests  on  the  second  one.  These 
two  bars  are  about  18  in.  apart.  Dirt  will  accumulate  on  the  top  of  A,  Fig.  166, 
if  square,  and  prevent  the  skip  from  occupying  its  true  position;  hence  the  use 
of  round  bars.  The  skip  being  5  ft.  high,  1/2  in.  of  dirt  or  ice  will  throw  the 
top  of  the  skip  i  2/3  in.  out  of  plumb. 

MINE  CAGES 

A  Three-deck  Man-cage. — The  hoisting  of  men  consumes  a  large  amount 
of  time  and  hence  reduces  the  amount  of  ore  that  may  be  hoisted  daily.  Wither- 
bee,  Sherman  &  Co.  recently  constructed  a  three-deck  cage  for  hoisting  men 
from  the  mine.  The  capacity  is  30  men  per  trip.  The  framework  consists  of 
channel  and  angle  iron,  while  the  sides  are  inclosed  with  3/8-in.  wire  screen, 
2 -in.  mesh.  The  front  of  the  cage  is  inclosed  by  means  of  sliding  screen  doors. 
The  cage  is  to  be  operated  in  an  inclined  shaft  and  for  this  reason  is  mounted 
upon  wheels.  It  is  built  so  that  the  floor  of  the  cage  is  horizontal,  while  the 
sides  conform  to  the  slope  of  the  shaft.  When  the  cage  is  not  in  use  it  will  be 
removed  from  the  shaft  by  means  of  a  block  and  pulley  which  operates  on  an 
I-beam  track.  The  cage  will  thus  be  carried  to  one  side  of  the  shaft  house  and 
entirely  out  of  the  way.  The  time  required  for  making  the  change  from  the 
ore  skip  to  the  man  skip  is  small.  The  present  skip  will  hoist  only  10  men  so 
that  with  this  new  cage  the  men  will  be  hoisted  in  one-third  of  the  usual  time. 

Hiawatha  Mine  Cage  (By  H.  L.  Botsford).— In  Figs.  167  and  168  are 
shown  a  type  of  cage  and  safety  catch  much  used  in  the  Lake  Superior  iron 
districts.  The  drawbar  A  is  free  to  slide  through  the  crosshead  or  supporting 
frame,  until  the  cage  is  carried  by  the  plate  and  jamb  nuts  B.  Chain  connec- 
tions between  the  drawbar  and  the  cam  shafts  cause  the  latter  to  rotate  when 
the  drawbar  is  raised.  The  springs  E  are  of  the  helical  type  and  are  placed  con- 
centrically around  the  cam  shafts,  one  to  each  shaft.  The  springs  are  fastened 
to  the  side  of  the  cage  and  to  collars  F  keyed  to  the  shafts.  Any  rotation  of  the 
shafts  produces  a  torsional  stress  in  the  springs.  Should  the  hoisting  rope  break, 
the  cam  shafts  are  turned  into  such  a  position  that  the  cams  are  brought  into 
contact  with  the  guides  and  cut  into  them  sufficiently  to  stop  any  downward 
motion.  This  cage  is  also  provided  with  two  bolster  springs  G  and  H,  one 
within  the  other  and  both  concentric  around  the  drawbar.  Their  purpose  is  to 
lessen  the  strains  in  the  hoisting  cable  due  to  a  too  sudden  starting  or  stopping 
of  the  cage,  and  also  to  draw  down  the  drawbar  in  case  of  the  failure  of  the  hoist- 
ing rope,  thus  permitting  the  full  force  of  the  cam-shaft  springs  E  to  be  expended 
in  forcing  the  cams  into  contact  with  the  guides.  There  are  several  holes  in  the 


244 


HANDBOOK  OF  MINING  DETAILS 


chain  pulleys  /,  and  the  spring  collars  F  for  the  fastening  of  the  chains  K  and 
the  springs  E.  This  permits  of  careful  adjustment  to  secure  the  proper  tension 
in  the  springs  E.  The  cage  is  substantially  a  type  made  by  the  Lake  Shore 


Splice  1 


FIG.    167. — HIAWATHA    CAGE    WITH   SKIP  ATTACHED. 

Engine  Works  of  Marquette,  Mich.,  and  is  shown  with  a  Kimberley  skip   at- 
tached below  it,  for  hoisting  ore. 

A  Light  Mine  Cage  (By  H.  L.  Botsford).— A  type  of  cage  used  in  the  West 
is  shown  in  Fig.  169.     This  cage  is  of  light  construction,  and  is  used  for  hoisting 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


245 


246 


HANDBOOK  OF  MINING  DETAILS 

S-"™"* 


SKIPS,  CAGES,  CARS  AND  BUCKETS  247 

small  loads.  The  springs  are  of  the  spiral  type,  two  in  number.  The  inner 
ends  of  the  spirals  are  fastened  to  collars  keyed  to  the  cam  shafts,  and  the  outer 
ends  are  bolted  together.  Unlike  the  cage  described  in  the  preceding  article, 
the  springs  are  not  attached  to  the  frame  of  the  cage.  The  cams  are  circular 
in  outline,  with  grooved  surfaces.  They  are  mounted  eccentrically  on  the  cam 
shafts,  which  gives  them  their  gripping  effect  upon  the  guides.  The  bonnets  of 
these  cages  are  usually  attached  by  hinges  so  that  they  may  conveniently  be 
swung  up  out  of  the  way  when  long  timbers  are  being  lowered.  It  will  be  noted 
that  the  guide  shoes  are  short,  whereas  in  the  other  cage  the  guide  shoes  were 
nearly  as  long  as  the  cage.  For  a  cage  of  this  type  which  is  intended  especially 
for  raising  small  loads  it  is  not  necessary  that  the  guide  shoes  be  long.  The  two 
sets  of  light  short  shoes  should  be  set  as  far  apart  vertically  as  can  be  conveniently 
done  as  the  greater  the  distance  between  them,  the  more  will  they  tend  to  steady 
the  cage  during  hoisting. 

SPECIAL  CARRIERS 

Harness  for  Lowering  Mule  Down  a  Shaft  (By  W.  F.  Boericke). — Where 
there  is  no  incline  by  which  mules  may  be  taken  underground,  the  animals  must 
be  lowered  either  in  a  specially  constructed  mule  cage,  or  swung  down  by  means 
of  a  harness  similar  to  the  one  here  described  and  illustrated  in  Fig.  170. 
Wherever  conditions  are  right,  the  preference  should  be  given  to  the  harness. 
The  mule  cage  is  heavy,  cumbersome,  difficult  to  get  the  mules  into,  and  its  use 
means  a  loss  of  time  in  getting  the  cage  in  and  out  of  the  shaft.  To  swing  a 
mule  with  a  harness  is  by  no  means  as  formidable  a  job  as  it  appears  at  first. 
The  harness  itself  is  a  simple  affair,  and  can  be  made  at  the  mine,  out  of  pieces 
of  old  canvas  or  rubber  belting,  securely  riveted  together.  The  dimensions  given 
in  the  sketch  are  adapted  for  a  poo-lb.  mule.  The  harness,  when  fitted  on  the 
mule,  should  be  fairly  snug,  but  the  straps  should  not  be  buckled  too  tightly. 
If  the  mule  is  accustomed  to  harness,  he  will  allow  it  to  be  put  on  without 
trouble.  The  parts  lettered  T  T  should  come  a  trifle  below  his  sides.  The 
part  S  should  be  low  enough  to  insure  that  the  mule  will  be  seated  firmly  when  he 
is  swung  into  the  shaft.  The  head  and  neck,  of  course,  come  through  the  space 
A.  When  all  is  ready,  the  mule  is  led  to  the  collar  of  the  shaft,  and  a  heavy 
chain  attached  to  the  hook,  and  made  fast  to  the  center  of  the  cage.  Planks 
should  be  laid  across  the  shaft,  so  that  as  the  mule  is  raised,  his  feet  will  not 
catch  in  the  timbers.  The  signal  is  given  to  hoist  slowly,  and  the  astonished 
animal  is  swung  out  over  the  shaft,  bearing  a  marked  similarity  to  a  dog  begging. 
The  planking  is  then  removed,  and  the  cage  slowly  lowered.  If  there  are  bad 
places  in  the  shaft,  it  may  be  well  to  tie  the  feet  together,  but  this  makes  a  delay 
at  the  bottom,  and  is  usually  unnecessary.  When  the  mule  is  near  the  bottom, 
a  rope  is  tied  to  the  back  of  the  harness,  and  the  animal  drawn  to  one  side,  so 
that  he  lands  on  four  feet.  In  an  actual  case,  from  the  time  the  mule  was  swung 


248 


HANDBOOK  OF  MINING  DETAILS 


into  the  shaft,  until  he  was  led  to  the  stables  at  the  bottom,  was  6  minutes,  the 
shaft  being  150  ft.  deep. 

Automatically  Discharging  Bailers  (By  W.  H.  Storms). — Many  mine 
managers  prefer  bailing  to  pumping  water  from  mines,  and  undoubtedly  there 
are  conditions  where  bailing  is  less  expensive  than  pumping.  Fig.  171  shows 
two  types  of  self-dumping  bailers;  one  a  cylindrical  valve  bucket,  the  other  a 
skip  fitted  with  a  hinged  valve  which  opens  to  admit  the  water  when  the  skip 


FIG.    170. — HARNESS    FOR   LOWERING    MULES. 

sinks  in  the  sump.  Both  are  arranged  to  operate  in  inclined  shafts.  The 
automatic-discharge  features  will  be  appreciated  by  those  who  have  had  no 
experience  with  bailers  of  this  kind. 

The  right-hand  illustration  shows  the  steel  barrel  on  the  skids  S  and  also  its 
position,  by  means  of  dotted  lines,  when  discharging.  This  is  accomplished  by 
cutting  out  a  section  A  of  the  skids  upon  which  the  bucket  slides.  This  section  is 
supported  on  a  pivot  B.  A  counterweight  W  holds  the  section  in  place  when  the 
bucket  is  below,  or  even  when  resting  upon  it  when  empty,  but  when  it  is  drawn 
up  out  of  the  shaft  filled  with  water  the  excess  of  weight  of  the  bucket  and  the 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


249 


water  below  the  pivot,  as  compared  with  that  above  it,  causes  the  loose  section 
of  the  skids  to  swing  backward  into  the  vertical  position  indicated  by  the  dotted 
lines.  The  engineer  then  lowers  the  bucket  without  leaving  his  station  at  the 
engine,  until  the  valve  spindle  V  rests  upon  the  floor,  which  forces  the  valve  up- 
ward, thus  allowing  the  water  to  escape  and  flow  away.  The  engineer  then 
raises  the  bucket  slowly  and  the  counterweight  W  pulls  the  skids,  with  the  empty 
bucket  upon  them,  back  into  position  and  the  bucket  is  lowered  again  into  the 
shaft. 


7    // 

FIG.    171. — AUTOMATIC   DISCHARGING   BAILERS. 

The  illustration  to  the  left  shows  an  ordinary  water-skip  with  a  hinged  valve 
in  the  bottom.  The  track,  generally  of  T-rail,  T1,  is  spiked  to  stringers  5  in  the 
headframe,  and  dumps  provided  for  both  ore  and  water  by  cutting  out  sections 
of  the  stringers  and  track  and  making  gates  G  G  as  shown.  The  gates  swing  on 
the  hinges  H  H,  that  for  the  water-dump  being  about  3  ft.  above  the  collar  of 
the  shaft.  When  a  skip  is  to  be  dumped  the  proper  gate  is  opened  and  upon  the 
arrival  of  the  skip  at  this  point  the  forward  wheels  follow  the  curved  rails  and 
run  out  upon  the  horizontal  track,  as  shown  in  the  sketch.  The  engineer  con- 
tinuing to  hoist  slowly,  the  lower  end  of  the  skip  is  lifted  from  the  main  rails  and 
its  contents  dumped.  There  is  one  thing  to  be  carefully  avoided  in  operating 
this  device.  When  the  skip  is  approaching  the  dumping  place  the  hoisting 
speed  must  be  slackened  to  a  moderate  rate  or  the  forward  wheels  are  liable  to 
collide  with  the  upward  extension  of  the  track  at  A ,  thus  doing  serious  damage 
to  the  headframe,  or  parting  the  cable.  The  bumper  keeps  the  wheels  from 


2  50 


HANDBOOK  OF  MINING  DETAILS 


running  so  far  forward  that  the  skip  will  not  automatically  descend  the  shaft 
again  when  empty.  By  having  a  movable  bumper,  however,  the  water-skip 
can  be  run  in  on  that  dump  and  secured  there  by  dropping  a  piece  of  light  timber 
between  the  rear  wheels  and  the  skids.  The  cable  can  then  be  detached  and 
made  fast  to  the  ore  skip.  In  this  way  either  ore  or  water  may  be  hoisted  in  the 
same  shaft  compartment,  by  using  two  suitable  skips. 

A  Two-ton  Water  Car  (By  Guy  C.  Stoltz).— The  type  of  water  car  used 
at  Mineville,  N.  Y.,  to  un water  Mine  21  is  shown  in  Fig.  172.  Two  cars  of  528 
gallons'  capacity  were  hoisted  in  balance  an  average  distance  of  450  ft.  on  a  60° 


FIG.    172. — WATER   SKIP   USED   AT   MINEVILLE,    N.    Y. 

double-track  incline.  They  were  automatically  filled  in  the  mine  and  automatic- 
ally discharged  at  the  surface  into  a  series  of  wooden  troughs.  The  greatest 
number  of  cars  hoisted  during  a  lo-hour  shift  was  812,  while  600  was  the  average 
rate  per  shift.  The  hoisting  capacity  at  maximum  speed  was  equal  to  a  pump 
fitted  with  a  lo-in.  discharge  delivering  715  gallons  per  minute.  The  average 
quantity  hoisted  was  528  gallons  per  minute.  The  water  tank  was  made  from 
a  lo-ft.  length  of  3-ft.  stack,  the  lower  end  headed  with  2-in.  pine  and  held  in 
place  by  a  2  X  2-in.  hardwood  ring  which  was  bolted  to  the  circumference  of  the 
stack  at  the  bottom.  The  top  was  not  headed.  The  bottom  timber  head  was 
reinforced  at  its  center  by  a  truss  of  3/4-in.  iron  bearing  on  a  4X4Xi2-in. 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


251 


wooden  strut.  The  tank,  which  was  attached  to  a  set  of  wooden  stringers  by 
flat  iron  hangers,  was  mounted  on  the  ordinary  skip  axles.  The  lower  lo-in. 
segment  of  the  tank  door  was  hinged  and  upon  lowering  the  car  into  the  water 
the  pressure  would  automatically  open  the  segment  and  allow  the  water  to  enter. 
As  the  car  was  hoisted  above  the  level  of  the  water  the  door  would  close  due  to  the 
hydraulic  pressure  of  the  contents.  The  door  was  automatically  opened  at  the 
dumping  point  on  the  surface  by  the  operation  of  a  system  of  lever  arms. 
These  were  attached  to  the  door  and  so  pivoted  that  a  plank  guide  A  would  inter- 
cept the  trolley  arm  B  and  lower  it  to  such  a  position  that  a  lateral  movement 
of  8  in.  toward  the  top  of  the  car  would  be  delivered  to  the  gate.  Upon  lowering 
the  car  the  gate,  which  was  heavier  than  the  reciprocating  system  of  levers, 
would  close.  Back  rails  should  be  provided  to  prevent  the  car  from  leaving  its 
track  as  it  enters  the  water. 

Scraper  for  Cleaning  Slopes. — The  stopes  of  the  Calumet  &  Hecla  mine 
dip  at  about  38°.     The  empty  stopes  are  not  filled  and  after  the  stoping  is  finished, 


FIG.    173. — A   LAKE   SUPERIOR  STOPE-FLOOR   SCRAPER. 

a  considerable  quantity  of  ore  is  left  on  the  floor,  especially  if  the  floor  is  rough. 
This  ore,  when  there  is  not  much  to  be  handled,  is  worked  down  to  the  level  by 
hand.  When  much  ore  has  accumulated  on  the  floor,  it  pays  to  use  the  scraper, 
the  construction  of  which  is  shown  in  Fig.  173.  A  sprag  is  set  in  the  top  of 
the  stope,  and  a  small  air  hoist  is  installed  at  the  bottom.  The  rope  that  goes 
from  the  hoist  to  the  rear  end  of  the  scraper  passes  through  a  pulley  carried  by 
the  sprag,  while  another  rope  from  the  hoist  goes  directly  to  the  front  ring  of  the 
scraper,  so  that  the  air  hoist,  besides  pulling  the  scraper  with  its  load  of  ore  in 
front  of  it  to  the  bottom  of  the  stope,  also  pulls  it  back  again.  The  scraper 
works  well  when  the  foot  wall  is  not  too  rough  and  practically  no  hand  shoveling 
of  the  ore  is  necessary,  but  if  the  ore  lies  in  pot  holes  in  the  foot  wall,  it  must  be 
shoveled  out  to  a  smoother  part  of  the  foot  wall,  where  the  scraper  can  get  at  it. 


252 


HANDBOOK  OF  MINING  DETAILS 


This  scraper  was  designed  by  Capt.  Samuel  Richards,  of  the  Calumet  &  Hecla 
company,  and  has  now  been  in  use  for  several  years,  both  in  the  amygdaloid 
and  in  the  conglomerate  stopes.  The  main  plate  of  the  scraper  is  5/16  in. 
thick,  and  is  strengthened  by  means  of  three  3X3/4-in.  iron  straps  that  come 
together  near  the  front,  so  as  to  distribute  the  load  to  the  haulage  strap.  A  ring 
is  provided  for  fastening  the  rope  from  the  hoist  to  the  front  end,  while  at  the 
rear  is  a  chain  that  is  fastened  to  two  eyebolts  that  go  through  the  two  outside 
straps.  To  this  the  return  rope  is  fastened.  There  are  also  riveted  to  the  rear 
of  the  scraper  two  plates  carrying  two  handles.  By  means  of  these  handles  the 
men  are  able  to  steer  the  scraper,  and  by  pulling  up  or  shoving  down  on  them 
regulate  the  quantity  of  ore  that  the  scraper  takes  on  its  trip  down  the  stope. 
In  case  the  scraper  has  a  tendency  to  ride  over  the  ore,  owing  to  the  compact  way 
in  which  it  lies  on  the  foot,  car  wheels  can  be  hung  on  these  handles,  and  the 
scraper  made  heavy  enough  to  dig  into  the  pile  of  ore. 

A  Scheme  for  Transporting  Lumber  (By  W.  F.  Du  Bois). — A  contrivance 
that  was  very  useful  to  me  in  transporting  lumber  is  illustrated  in  Fig.  1 74.     The 


FIG.    174. — A   LUMBER    LIZARD. 

wagon  road  ended  3/4  of  a  mile  from  the  mine  where  I  wished  to  put  up  an 
office  and  mine  buildings.  The  slope  from  the  end  of  the  road  to  the  mine 
was  between  30  and  40°,  so  that  it  was  impossible  to  go  down  with  a  wagon. 
The  " lizard"  used  is  2  1/2  ft.  wide,  2  ft.  long  and  made  of  2-in.  plank.  On  the 
top  is  a  piece  of  pine  3X5  in.,  beveled  so  that  it  is  3  in.  thick  on  the  back  and 
i  1/2  in.  in  front  and  spiked  to  the  2-in.  plank  with  2od.  nails.  The  first  planks 
or  boards  to  be  hauled  are  spiked  on  top  of  the  3X  5-in.  piece  with  2od.  nails  and 
the  successive  layers  of  boards  nailed  to  each  lower  layer.  After  1 8  or  20  boards, 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


253 


1 8  ft.  long,  are  securely  spiked,  an  ordinary  i2-ft.  log  chain  is  put  around  the 
boards,  back  of  the  3  X  5-in.  plank.  The  end  of  the  chain  is  fastened  to  a  single- 
tree by  a  grabhook. 

One  horse  could  easily  pull  the  load  down  the  back  of  the  ridge  to  the  mine. 
On  arriving  at  the  mine  the  chain  was  thrown  off  and  each  board  pried  loose. 
The  chain  and  singletree  were  hung  on  the  harness  and  a  boy  carried  the  lizard 
as  he  rode  the  horse  to  the  lumber  pile  after  another  load.  The  lizard  lasted 
1 2  loads.  Four  trips  a  day  were  made. 

A  Wagon  Oil  Tank  (Chester  Steinem). — In  view  of  the  increasing  use  of 
crude  oil  as  a  fuel  and  for  combustion  in  oil  engines,  a  description  of  a  tank 


2-in.  R. 


Provide  with 
Sliding  Gate 
for  Manway 


Section  A-B 

Two  %  -in.  Steel  Plates 

Kiveted  in  eacb  Tank, 

to  act  as  .baffles. 


•J-in,  Flange,  2-ln.  Nipple, 
2-in.  Gate  Valve, 
2-U-  Plug  with  Chain. 

6-in. 

— 2-f-W- 


}<Mn.  U-bolt  Handle 

4-in.  wide,  2-iu.  high, 

Bolted  thus** 

Slotted  for  H-iu. 

Swing  Bolts 


6-in. 


.Steel  Top  Plate, 
Hinged  with  Rings  and  bolted 
with  Swing  Bolts  to  Lower  Cast- 
ing which  is  Riveted  to  Dome, 
i-in.  Vent  Cock. 

Hinge  Rings. 
—Lugs  on  Catting  for  holding  Swing  Bolts. 


'l  L—  «4trWf4fc  4  

'•^~rr-r^-'  ^4-Va.  Pop  Safety  Valve       | 

n 

:    |               tt.-ln.-i 
."    1            Baffle  Plate  \ 

U         ! 

•j^.3/^in.  Baffle  Plate      ; 

Capacity          ;!               e-in. 
608  Gal.          :|             UJ^arfMa, 

?!         HJ    0              : 

"""^j-in.  flange 
and  Plug 

u||   IT           7x7 

2-in.  Fittings 

End  Elevation. 

Two  heavy  L-Irons  are  Riveted  to  Tank  a8  auuro- 

so  as  to  Fit  over  a  6  i  6-in.  Timber  which 
is  fastened  to  Bolster.  5-in.  from  each  End 
of  L-lron  a  %-in.  Hole  is  Bored  and  a 
Bolt  run  through  Timber. 

FIG.  175. — TANK  FOR  WAGONS  FOR  HAULING  FUEL  OIL. 

designed  specially  for  transporting  crude  oil  is  of  interest.  In  the  Mogollon 
district,  oil  has  displaced  wood  as  fuel  for  generating  power,  although  wood  is 
plentiful.  It  commends  itself  as  being  cheaper  for  many  purposes,  and  to 
supply  outlying  districts  a  wagon-tank  is  often  necessary.  D.  Ford  Mc- 
Cormick  designed  the  tank  shown  in  Fig.  175.  It  is  giving  good  service  on 
a  99-mile  haul  over  rough  mountain  roads. 

UNL9ADERS  AND  DUMPING  DEVICES 

An  Automatic  Bucket-tripping  Device.— An  ingenious  bucket-tripping 
device  especially  adaptable  for  use  in  developing  prospects  is  shown  in  Fig.  176. 
The  bucket  is  made  with  lugs,  which  travel  on  skids,  set  below  its  center  of  gravity. 
When,  however,  these  lugs  reach  the  notch  A  the  bucket  is  held,  and  as  soon  as 


254  HANDBOOK  OF  MINING  DETAILS 

the  hoisting  cable  is  relaxed  it  swings  about  the  lugs  as  an  axis  and  dumps  in  the 
bin  or  on  a  grizzly  as  the  case  may  be.  The  bar  B  prevents  the  bucket  dropping 
over  too  far.  To  lower,  the  bucket  is  hoisted  until  the  lugs  clear  the  end  of  the 
trip  C,  then  it  is  lowered.  The  trip  swings  down  and  being  arrested  at  D  by  a 
projecting  i/2-in.  angle,  forms  a  track  over  the  notch  A  into  which  the  lugs 
engaged  in  hoisting.  The  trip  is  heavier  on  the  straight  end,  so  immediately 
the  lugs  pass  off  it  swings  back  into  position.  This  simple  device  is  valuable  for 
small  mines  or  prospects  where  the  shaft  is  inclined  at  an  angle  less  than  about 
70°,  as  it  saves  the  labor  of  the  man  who  usually  has  to  swing  and  dump  the 
bucket  or  attach  the  dumping  line  to  the  bottom  of  the  bucket. 


Safety  Bar 


FIG.    176. — AUTOMATIC  BUCKET  TRIP. 

Safety  Dump  for  Sinking  Bucket. — The  accompanying  sketch,  Fig.  177, 
shows  a  satisfactory  and  novel  method  of  automatically  dumping  a  sinking 
bucket.  The  scheme  was  used  in  sinking  from  the  3150  to  the  3300  level  in  the 
Kennedy  mine,  Jackson,  Amador  county,  Calif.  Sinking  was  conducted  in  the 
third,  or  pipe  and  manway,  shaft  compartment  so  that  hoisting  was  not  inter- 
rupted. At  the  upper  level  station  a  wooden  wing  door  W  is  hinged  so  that  when 
released  after  the  bucket  has  been  raised  above  the  level,  it  swings  from  a  nearly 
vertical  position  to  one  across  the  shaft  compartment  as  is  shown  in  the  drawing. 
In  this  position  it  completely  closes  the  shaft.  A  second  door  X  built  of  sheet 
iron  is  hinged  at  its  lower  edge  to  the  wing  door  and  fastened  to  it  by  a  chain  C 
at  its  upper  edge.  There  is  an  iron  lug  L  riveted  on  the  upper  side  of  the  iron 
door.  From  the  bottom  of  the  bucket  is  rigidly  suspended,  by  four  iron  straps, 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


255 


a  circular  hoop  R  of  i-in.  drill  steel.  When  the  bucket  is  raised  above  the  level, 
the  same  lever  that  drops  the  wing  door  throws  out  the  dogs  or  chairs  D  which 
hold  the  crosshead  while  the  bucket  is  dumping.  On  releasing  the  bucket  the 
iron  hoop  engages  the  lug  and  the  weight  of  the  loaded  bucket  swings  down  the 
iron  door  into  the  position  shown  by  the  dotted  lines.  The  chain  keeps  this 


Shaft  3rd  Sinking 

Compartment 


FIG.    177. — ARRANGEMENT   USED  AT   KENNEDY   MINE   FOR  DUMPING   SINKING   BUCKET. 

flap  door  from  swinging  beyond  the  position  indicated.  The  bucket  is  then 
hoisted,  this  swinging  the  iron  door  back  against  the  wooden  wing  door.  The 
engineer  then  pulls  back  the  wing  door  and  at  the  same  time  releases  the  dogs 
holding  the  crosshead.  The  bucket  may  then  be  lowered  for  another  load. 
The  operation  of  dumping  is  automatic  save  for  the  swinging  of  the  wing 
door.  However,  the  man  operating  the  hoist  attends  to  this  without  leaving  his 
position  at  the  engine.  The  men  at  work  in  the  shaft  are  absolutely  protected 
from  falling  rocks  while  the  bucket  is  being  dumped. 


256 


HANDBOOK  OF  MINING  DETAILS 


Front  View  of  Bucket 
*.         6 


Air- 
Cylinder 


Vertical  Section 

FIG.    178.— SELF-DUMPING    BUCKET   USED   AT   BULLY  HILL   MINE. 


SKIPS,  CAGES,  CARS  AND  BUCKETS  257 

Self-dumping  Bucket  for  Winze  (By  Lawrence  May). — The  self-dump- 
ing bucket  arrangement  shown  in  Fig.  178.,  was  designed  to  meet  peculiar  condi- 
tions for  handling  ore  underground;  large  capacity  was  also  required.  As  the 
shaft  is  a  winze  shaft  and  in  extremely  hard  rock,  work  above  the  station  level 
is  expensive.  Accordingly,  the  cost  of  a  skip  installation  put  it  out  of  considera- 
tion, and  the  arrangement  of  this  bucket  on  a  crosshead,  with  platform  for  men 
and  timber  was  installed.  The  bucket  is  rectangular,  24  in.  wide,  30  in.  long, 
and  30  in.  deep.  A  lug  projects  3  in.  from  the  side  and  is  set  behind  the  center. 
Two  "ears"  on  the  upper  rim  of  the  bucket  are  drilled  for  safety  hooks  hung 
from  the  crosshead  with  flexible  steel  cables.  The  door  upon  which  the  bucket 
dumps  its  contents  is  mounted  on  the  shaft  N;  at  A  a  heavy  piece  of  angle  iron 
on  the  under  side  of  the  door  projects  beyond  the  shaft  timber,  and  to  it  are 
attached  the  ropes  which  operate  the  door.  To  allow  this  angle  iron  to  pass, 
the  guide  is  cut  at  C.  The  dumping  mechanism  consists  of  the  two  arms  B,  to 
which  is  bolted  a  heavy  iron  strip  carrying  two  stirrups  S,  the  trigger  arm  T,  and 
the  weight  arm  W,  all  firmly  keyed  on  the  shaft  R.  In  operation,  the  bucket  is 
hoisted  far  enough  to  clear  the  door.  The  engineer  then  throws  a  three-way 
valve,  admitting  compressed  air  to  the  cylinder  shown.  The  piston  is  forced 
down,  pulling  the  door  by  the  arm  A,  to  its  closed  position  on  the  bumper  Q. 
As  the  door  descends,  it  strikes  the  trigger  T,  throwing  the  dumping  mechanism 
into  the  position  shown  by  full  lines.  The  bar  holding  the  stirrups  rests  on  the 
timbers  O.  The  whole  gear  is  now  held  in  position  by  air  in  the  cylinder. 
The  engineer  lowers  the  bucket,  the  lugs  drop  into  stirrups  5,  and  the  bucket 
dumps  its  contents  on  the  door  by  turning  about  the  lugs  as  an  axis.  After 
dumping,  the  bucket  is  raised  to  clear  the  door.  The  engineer  releases  the 
air  in  the  air  cylinder.  The  chain  counterweight  pulling  on  arm  A ,  draws  the 
door  into  its  clearance  position.  As  the  door  rises,  the  weight  W  causes  the 
dumping  mechanism  to  assume  the  position  shown  by  dotted  lines  and  the  shaft 
is  clear  for  lowering  the  bucket.  The  bucket  drops  on  a  low  truck,  is  quickly 
unhooked  and  run  away.  A  loaded  bucket  is  run  under  the  crosshead,  hooked 
on,  and  is  ready  for  hoisting.  A  large  weight  is  needed  to  start  the  door  up,  but 
less  as  it  ascends.  A  solid  weight  heavy  enough  to  start  the  door  would  pull  it 
too  severely  on  the  finish.  Therefore  a  chain  is  used,  and  after  the  door  starts 
and  moves  a  few  inches,  the  end  of  the  chain  rests  on  a  platform.  As  the  door 
ascends,  weight  is  taken  off  the  pulling  rope,  by  the  chain  piling  up  on  the  plat- 
form. Thus  the  door  is  almost  perfectly  counterbalanced  in  any  position  and 
operates  smoothly. 

Automatic  Bucket  Dump. — The  automatic-dump  apparatus  shown  in 
Fig.  179,  is  the  invention  of  R.  H.  Pascoe,  former  superintendent  of  the  Burke 
mines  of  the  Federal  Mining  &  Smelting  Co.,  Cceur  d'Alene  district,  Ida.  The 
main  features  of  construction  and  operation  are  clearly  indicated  by  the  engrav- 
ing. The  laterally  extending  trunnions  A  on  the  bucket  (which  is  suspended  by 
chains  from  a  crosshead)  engage  in  the  trunnion  recess  B  on  the  skids  when  the 
17 


258 


HANDBOOK  OF  MINING  DETAILS 


upper  end  of  the  bucket  comes  in  contact  with  the  deflector  opposite  to  the  skids, 
thus  causing  the  bucket  to  capsize  and  discharge  its  contents  into  the  chute  or 
other  receptacle.  In  the  engraving  the  deflector  is  shown  as  being  composed 
of  wooden  pieces  faced  with  iron;  3-in.  angle  irons  are  used  for  this  purpose  in  the 
Morning  mine  of  the  Federal  company.  The  crosshead  is  preferably  con- 
structed of  steel  I-beams  or  angle  irons,  properly  braced,  with  an  eyebolt  for 
suspension  from  the  cable.  The  bucket  is  suspended  from  the  crosshead  by 
a  pair  of  eyebolts  connected  with  chains  of  sufficient  length  to  allow  easy  dump- 


Long-itudinal  Section 
Shaft 


FIG.    179. — AUTOMATIC   DUMPING    BUCKET. 


ing.  The  crosshead  runs  between  a  single  pair  of  timber  guides  secured  in 
proper  alignment.  If  desired  a  safety  clutch  can  be  applied  to  the  crosshead. 
This  apparatus  has  been  thoroughly  tested  under  actual  working  condi- 
tions in  the  mines  of  the  Federal  and  other  companies  operating  in  the  Cceur 
d'Alenes.  By  its  use  a  i-ton  bucket  can  be  hoisted,  dumped,  and  delivered  back 
to  the  bottom  of  loo-ft.  shaft  in  90  seconds,  this  having  been  proved  in  the  actual 
work  of  sinking  two  three-compartment  shafts  300  ft.  each.  This  work  also 
demonstrated  a  i-ton  bucket  would  more  than  take  care  of  the  rock  broken,  in 


SKIPS,  CAGES,  CARS  AND  BUCKETS  259 

addition  to  hoisting  the  men  and  supplies.  One  great  advantage  of  using  this 
apparatus  in  shaft  sinking  lies  in  the  safety  afforded  the  men.  No  rock  falls 
back  into  the  shaft,  and  the  quick,  positive  action  and  freedom  from  sway  and 
sideplay  reduces  confusion  when  ready  to  blast.  As  the  bucket  rides  as 
steadily  as  a  skip,  it  is  unnecessary  to  line  a  shaft  in  good  ground.  In  sinking 
two-  or  three-compartment  shafts,  the  chain  on  one  side  can  be  unhooked  and 
the  bucket  taken  to  any  part  of  the  shaft  for  loading,  thus  enabling  this  opera- 
tion to  be  performed  readily  and  conveniently.  After  loading,  the  bucket  is 
pulled  back  into  position  by  the  hoist  and  the  loose  chain  hooked  on,  when  the 
load  is  ready  for  hoisting.  Owing  to  vibration  being  taken  up  by  the  chains,  a 
bucket  fitted  with  a  valve  makes  an  ideal  bailer.  Dumping  can  be  effected  at 
any  level  at  or  below  the  hoist  station,  making  it  unnecessary  to  move  the  hoist 
until  the  limit  of  capacity  of  the  engine  is  reached,  which  cannot  be  done  with 
an  ordinary  bucket  without  the  services  and  extra  expense  of  a  topman  at  the 
dumping  point.  If  the  shaft  has  more  than  one  compartment  this  apparatus 
is  best  installed  in  the  pipe  compartment. 

Method  of  Handling  Sinking  Buckets  (By  W.  B.  Baggaley).— The 
method  of  removing  buckets  from  the  cage  at  one  of  the  newer  Lake  Superior 
copper  properties,  which  is  still  in  the  development  stage  is  shown  in  Fig.  180. 
A  vertical,  five-compartment  shaft  is  being  sunk  to  an  ultimate  depth  of  4000  ft. 
Two  compartments  are  being  used  for  hoisting  rock  and  water  and  lowering 
timber,  etc.  A  floor  plan  and  elevation  of  part  of  the  shaft  house"  are  shown  in 
the  illustration. 

On  nearing  the  surface  the  cage  slows  down  sufficiently  to  pick  up  the  shaft 
cover,  and  then  proceeds  to  an  elevation  of  15  ft.  above  the  floor  of  the  shaft 
house.  Chairs  are  used  in  the  shaft  to  prevent  the  cage  descending.  The 
floor  car,  operated  by  the  compressed-air  cylinder  shown,  and  having  the  bucket 
car  upon  it,  is  run  over  the  shaft.  The  cage  is  not  attached  to  the  hoisting  rope, 
but  rests  upon  a  lug,  while  the  bucket  hangs  from  chains  which  are  permanently 
fastened  to  the  end  of  the  rope  itself.  Consequently,  when  the  bucket  is  lowered 
the  cage  remains  on  the  chairs.  The  full  bucket  is  then  lowered  to  the  car  below, 
which  has  a  mounted  and  pivoted  frame  into  which  the  bucket  fits.  The  floor 
car  is  then  pulled  back  to  the  normal  position,  and  as  it  stops  suddenly,  suffi- 
cient impetus  is  given  the  car  to  assist  materially  the  trammers,  who  push  it  to 
the  dump.  It  will  be  noted  that  the  tram  car  is  of  such  dimensions  that  it  could 
not  drop  down  the  shaft  if  any  accident  should  occur. 

An  empty  bucket  is  now  placed  on  the  rope,  and  hoisted  until  the  lug  lifts 
the  cage  from  the  chairs.  The  latter  are  then  drawn  back,  allowing  the  cage  to 
be  lowered  slowly  until  the  shaft  cover  comes  to  rest  on  the  first  set  of  stringers 
at  the  level  of  the  floor.  The  shaft  cover  has  a  hole  in  the  center  through 
which  the  hoisting  rope  runs.  The  cage  is  necessary  to  act  as  a  guide  for 
the  bucket,  which  contains  about  2  tons  of  rock,  and  which  is  hoisted  at  the 
rate  of  3000  ft.  per  minute. 


260 


HANDBOOK  OF  MINING  DETAILS 


This  arrangement,  which  keeps  the  shaft  covered  at  all  times,  not  only  pre- 
vents anyone  falling  in  at  the  surface,  but  also  safeguards  the  miners  working 
below,  from  having  anything  dropped  on  hem  when  the  cage  is  being  loaded 
with  drill  steel,  etc.  The  loading  of  shaft  timbers  which  are  swung  under  the 
cage,  is  greatly  facilitated.  Also  the  substitution  of  a  bailer  in  place  of  the  cage 

/  Edge  of  Floor  •     Guide 

Relief  Valve 

Piston  \         ^x"*" 
r-± \~.^C-___ 


I  if    'I 

Ijll   n  Compressed — Ji 

Air  Pipes 

I 


~""1 

~     -     '     -     - 

Ij 

YffSZw 

Elevation 

^^^ 

\ 

1 

' 

/, 

1 

FIG.    ISO. — SURFACE   ARRANGEMENT    FOR   HANDLING    SINKING    BUCKETS    BY    COMPRESSED    AIR. 

is  made  easier  and  safer.  The  services  of  two  men  are  saved  underground,  by 
having  the  cage  rest  upon  the  lug,  as  the  latter  comes  to  rest  on  chairs  at  the  low- 
est level  and  the  bucket  continues  to  the  bottom  of  the  shaft.  Ordinarily,  an 
auxiliary  hoist  is  installed  at  the  lowest  level,  which,  being  operated  by  com- 
pressed air,  is  much  less  efficient. 


SKIPS,  CAGES    CARS  AND  BUCKETS 


261 


Types  of  Skip  Dumps  in  New  York  Iron  Mines  (By  Guy  C.  Stoltz).— 
The  drawings  presented  in  Figs.  i8ia  and  iSib  illustrate  several  methods 
employed  for  dumping  skips  in  the  head-frame  storage  bins  at  the  magnetite 
mines  of  northern  New  York.  The  car  dump,  shown  in  Fig.  i,  has  been  used 
at  the  Forest  of  Dean  mine  in  Orange  county.  Here  the  regular  2-ton  mine 


7'Tread 


FIG.    I. 


FIG.    2. 


FIG.    3 


FIG.    l8ia. — TYPES   OF  SKIP  DUMPS   IN  NEW  YORK   IRON   MINES. 

cars,  equipped  with  an  end-locking  door,  are  hoisted  about  1800  ft.  up  a  23° 
slope,  to  a  point  near  the  surface  where  the  inclination  is  increased  to  45°.  At 
the  storage  bin  the  lever  which  actuates  the  locking  device  on  the  door  is  mechan- 
ically raised  on  encountering  a  flat  iron  truss  A  bolted  to  the  rail  stringer,  the 


262 


HANDBOOK  OF  MINING  DETAILS 


ore  being  discharged  from  the  rear  of  the  car.  The  car  is  then  lowered  to  the 
hoisting  level,  the  door  locked,  the  cable  disengaged  and  the  car  is  trammed  to 
the  stope  to  be  filled.  The  cable  provided  with  a  locking  hook  is  then  attached 
to  a  loaded  car  which  is  in  waiting  at  the  foot  of  the  incline. 

The  usual  method  of  dumping  adopted  on  incline  hoists  at  Lyon  mountain, 
Arnold  hill  and  Mineville  is  shown  in  Fig.  2.  At  Mine  21,  Mineville,  the  2-ton 
skip  cars  are  hoisted  in  balance  on  a  57°  slope,  800  ft.  from  the  lowest  level,  and 
are  dumped  above  the  grizzlies  by  allowing  the  front  wheels  of  4-in.  tread  to 
leave  the  main  stringers  and  take  an  almost  horizontal  course  on  a  set  of  auxiliary 


l» 


FIG.   l8l  b. — TYPES    OF   SKIP   DUMPS    IN   NEW   YORK   IRON   MINES. 


stringers,  while  the  rear  wheels  of  y-in.  tread  run  over  the  dumping  point  on  the 
inclination  of  the  main  stringers.  No  guides  are  used  on  the  hoist  and  the  front 
wheels  of  the  skip  are  prevented  from  lifting  off  the  rails  in  hoisting  by  having 
the  bail  press  against  lugs  riveted  on  each  side  of  the  skip. 

The  wheels  are  stationary  on  the  axle,  the  latter  turning  in  brass-lined 
journals.     This  method  of  stationary  wheels  is  to  be  recommended  since  the 


SKIPS,  CAGES,  CARS  AND  BUCKETS  263 

wheels  cannot  become  loose  or  wabbly  by  wearing  of  wheel  hubs  or  axles  and 
consequently  reduces  to  a  minimum  the  chances  of  skips  jumping  the  tracks. 
In  case  of  an  overwind  through  the  dump  the  skip  is  hoisted  in  its  dumping 
position  of  45°,  since  lugs  on  the  skip  at  the  back  bear  against  the  bail  as  the  skip 
assumes  the  angle  of  discharge. 

The  skip  used  at  the  Cheever  mine,  near  Port  Henry,  N.  Y.,  is  shown  in 
Fig.  3.  The  4-ton  skip  cars  are  dumped  by  having  the  front  wheels  of  4-in. 
tread  keep  to  the  30°  inclination  of  the  main  stringers,  while  the  rear  wheels 
(which  are  cast  with  the  usual  4-in.  tread  and  diameter  of  the  front  wheel 
together  with  smaller  wheels  of  like  tread  and  smaller  diameter)  by  means  of  the 
extended  tread  pass  over  a  timber  truss  which  causes  the  skip  to  assume  the 
angle  of  discharge.  In  case  of  an  overwind  the  upper  members  of  the  dumping 
truss  provide  for  this  and  are  inclined  toward  the  inclination  of  the  main  stringers, 
so  the  skip  on  descending  would  readily  stay  to  the  stringers  and  lower  over 
the  truss  and  down  the  shaft. 

The  skip-dumping  arrangement,  in  Fig.  4,  used  by  Witherbee,  Sherman  & 
Co.,  at  the  Harmony  A  and  B,  Smith,  Joker  and  Bonanza  mines,  in  the  Mineville 
district,  is  well  designed  and  differs  much  from  the  usual  types  of  dump.  The 
fore  and  rear  wheels  have  the  same  dimensions  and  are  so  guided  at  the 
dump  that  the  tilting  of  the  skip  is  positive,  and  in  case  of  an  overwind  the  back 
track  guides  will  enable  the  skip  to  right  itself  quickly.  At  the  Joker  steel 
headframe  4-ton  skips  are  dumped,  while  the  same  method  is  applied  at  all  of 
the  hoistways,  vertical  and  inclined. 

The  dump  used  by  the  Port  Henry  Iron  Ore  Co.  in  the  steel  headframe  at 
the  Clonan  shaft  is  shown  in  Fig.  5.  The  4-ton  Kimberley  skips  are  turned  on 
the  axle  A  by  means  of  the  rollers  B  taking  a  course  away  from  the  vertical  guides 
as  described  by  the  angle-iron  guides  until  the  horns  C  intercept  the  rollers  D, 
whereupon  the  skip  rollers  B  are  elevated  to  the  upper  angle-iron  guides.  The 
skip  overwinds  at  approximately  the  angle  of  discharge. 

Throughout  the  district,  the  hoisting  cables  are  plow  steel,  i  in.  to  i  1/8  in. 
in  diameter,  and  are  generally  attached  by  passing  through  a  clevis  on  the  bail  of 
the  skip,  being  lapped  3  ft.  and  held  by  three  to  six  grips.  Iron  head  sheaves 
are  5  to  8  ft.  in  diameter.  Eight  to  14  ft.  are  allowed  for  overwinding.  The 
usual  gage  of  skipways  is  4  feet. 

[The  arrangement  illustrated  in  Fig.  5  of  Mr.  Stoltz's  article  is  that  of  the 
ordinary  Kimberley  dump.  At  the  Kennedy  mine,  at  Jackson,  Amador 
county,  Calif.,  an  improvement  of  this  idea  is  used  by  which  the  necessity  for 
lugs  on  the  skips  is  obviated.  In  place  of  having  the  "plate-dump  roller," 
indicated  at  J9,  which  engages  the  horns  C  on  the  skip  and  thus  makes  it  possible 
to  further  elevate  the  bottom  of  the  skip,  two  hooks  of  flat  iron,  spaced  about 
2  ft.  apart,  are  hung  from  the  headframe  so  as  to  engage  the  lip  of  the  skip 
as  it  is  tilted  by  the  curved  tracks.  These  hooks  support  the  skip  while  the 
bottom  is  being  raised,  just  as  does  the  bar  on  which  the  horns  catch  in  the  skip 


264 


HANDBOOK  OF  MINING  DETAILS 


A 


H\\ 


I 

I 
*  pV 

1 

I  L 

ij 
I 
ji 

*l 

I 

!i 

ij 

r 

4 

i 
R 

i 

• 

I 

r 

v           / 

•FT 

ft 

ii 

tl 

:  1 

FIG.    182. — SELF-DUMPING   SKIP  USED  AT   ORIGINAL  MINE,    BUTTE,   MONT. 


SKIPS,  CAGES,  CARS  AND  BUCKETS  265 

used  at  Port  Henry.  As  the  hooks  are  free  to  swing  there  is  less  jar  on  the  skip 
when  they  are  used  than  is  usual  with  the  ordinary  device. — EDITOR.] 

The  Original  Consolidated  Self-dumping  Skip. — A  self-dumping  skip 
of  novel  and  satisfactory  design  has  been  worked  out  and  used  for  some  time 
at  the  Original  Consolidated  mine,  Butte,  Mont.  In  fact,  so  satisfactory  has 
the  operation  of  these  skips  been  at  the  Clark  mines,  that  they  have  been  copied 
by  the  Amalgamated  company,  and  more  recently  by  the  Miami  Copper  Co., 
at  Globe,  Ariz.  The  particular  feature  of  the  design  of  the  skip  is  the  dump 
mechanism  which  is  simple  and  self-contained.  The  skip  is  durable  and  also 
of  convenient  proportions. 

The  details  of  the  Original  skip  are  shown  in  Fig.  182.  As  will  be  noticed, 
the  guide  shoe  extends  over  the  full  length  of  the  skip  bail.  This  is  one  of  the 
most  important  features  of  the  design,  for  the  usefulness  of  any  hoisting  convey- 
ance is  limited  the  life  of  the  shoes.  By  distributing  the  wear  over  a  large  sur- 
face the  life  of  these  is  prolonged  materially.  This  is  especially  necessary  with 
the  fast  hoisting  practised  at  Butte. 

The  portion  of  the  shoe  marked  B  is  not  connected  to  the  bail,  as  will  be 
explained.  The  skip  is  hung  from  the  bail  on  the  axles  C.  The  portion  of  the 
guide  shoes  B  is  riveted  to  plates  D  on  the  skip  body,  instead  of  being  fixed  to 
the  bale.  The  support  afforded  by  this  part  of  the  shoe  serves  to  keep  the  skip 
in  a  vertical  position  in  the  shaft.  Slotted  steel  bars  F  are  bolted  to  the  skip 
body  and  rotate  about  E  as  pivots.  The  skip  bail  has  a  projection  which  extends 
over  the  lower  end  of  the  slotted  bars  and  the  bolts  G  pass  through  the  slots  and 
the  extension  of  the  skip  bail.  In  dumping  these  bolts  slide  up  and  down  the 
slots. 

As  usual  with  self-dumping  skips,  there  is  a  roller  H  fastened  on  either  side 
of  the  skip  at  a  point  near  its  top  and  close  to  its  front  edge.  These  rollers  en- 
gage, at  the  discharge  point,  in  tracks  curved  up  and  away  from  the  shaft  so 
that  as  the  skip  is  hoisted  it  is  tilted  forward  about  the  axles  C  and  discharges  its 
contents.  As  the  skip  swings  down,  the  bolts  G  slide  up  the  slotted  bars  F  which 
swing  between  the  skip  and  its  bail.  The  guides  in  the  shaft  (or  headframe) 
must,  however,  be  cut  away  at  the  point  of  discharge  so  as  to  allow  the  portion  of 
the  shoe  B,  that  is  fixed  to  the  skip  to  swing  free.  The  skip  turns  over  until  the 
bolts  reach  the  end  of  the  slotted  bars.  On  lowering  the  skip,  the  rollers  run 
back  down  the  curved  guide  track  and  the  skip  body  is  again  swung  into  a 
vertical  position.  The  governing  action  of  the  slotted  bars  is  more  positive 
and  quicker  than  that  of  the  arrangement  of  projecting  lugs  to  engage  a  cross- 
bar, ordinarily  used  on  self-dumping  skips.  The  top  of  the  curved  guides  for 
the  rollers  is  cut  away  at  the  point  reached  by  the  rollers  when  the  skip  is  tilted 
as  far  as  the  slotted  dump  bars  permit.  This  allows  the  dumped  skip  to  be 
raised  farther  so  that  slight  overwinding  does  no  damage. 

The  skips  at  the  Original  mine  are  n  ft.  4  in.  deep,  3  ft.  5  in.  from  back  to 
front  and  3  ft.  4  in.  wide.  The  total  length  of  the  guide  shoes  is  14  ft.  2  1/2  in., 


266 


HANDBOOK  OF  MINING  DETAILS 


i  ft.  2  1/2  in.  being  cut  away  from  the  bail  at  a  point  5  ft.  below  the  top.  The 
diverting  rollers  are  centered  at  a  point  8  ft.  1/2  in.  from  the  bottom  of  the  skip 
and  the  bail  hung  2  ft.  i  1/2  in.  above  the  bottom.  The  slotted  bars  are  cen- 
tered 2  ft.  8  in.  above  the  skip  bottom.  The  skip  is  constructed  of  5/i6-in. 
steel. 

Skip  Changing  Device  at  Leonard  No.  2  Shaft. — A  device  by  which  skips 
and  man  cages  are  interchanged  in  2  1/2  minutes  is  used  on  the  steel  headf  rame 


Fixed  Block 


To  Air  opecat.ec 
Cylinder 

.—  Fixed  Block 


FIG.     183. — ^ARRANGEMENT     FOR     INTERCHANGING     SKIPS     AND     CAGES     ON     LEONARD     NO.     2 

HEADFRAME,    BUTTE. 


at  the  No.  2  shaft  of  the  Leonard  mine  at  Butte,  Mont.  As  shown  in  the  dia- 
grammatic sketch,  Figs.  183,  a  portion  of  the  guide  in  the  shaft  is  cut  away  and 
pivoted  at  the  top  so  that  the  lower  end  may  be  swung  over  to  either  of  two  other 
fixed  guides  on  which"cages  and  skips  are  supported  when  not  in  use.  The  move- 
ment of  the  loose  section  of  the  runners  is  effected  by  a  compressed-air  cylinder. 


SKIPS,  CAGES,  CARS  AND  BUCKETS  267 

A  rope  is  fastened  at  one  end  to  a  rod  that  is  connected  to  the  guide,  passed  over 
blocks,  as  shown  in  the  sketch,  and  the  other  end  fixed  to  the  piston  rod  of  the 
air  cylinder.  Movable  lugs  operated  by  hand  levers  are  so  arranged  as  to  en- 
gage the  moving  section  of  the  guide  at  the  proper  point  so  that  it  will  form  a 
continuation  of  a  fixed  guide  for  the  man  cages.  By  throwing  these  lugs  back 
the  guide  may  swing  over  against  fixed  lugs  so  as  to  form  a  continuation  of  a 
fixed  guide  for  skips.  These  two  fixed  guides  are  made  of  angle  iron.  When 
it  is  desired  to  take  off  the  skip  and  use  man  cages,  the  skip  is  hoisted  above  the 
lower  end  of  the  section  of  movable  guide,  this  section  is  swung  out  against  the 
fixed  lugs,  the  skip  lowered  on  to  the  fixed  angle-iron  guide  and  the  hoisting 
cable  disconnected.  The  section  of  the  guide  is  then  swung  down  to  engage 
the  movable  lugs,  which  are  thrown  out,  and  the  hoisting  cable  fastened  to  the 
man  cage  which  is  then  hoisted  far  enough  to  allow  the  section  of  guide  to  be 
swung  back  into  the  vertical  position.  In  interchanging  skips  and  cages  it  is 
necessary  to  fasten  the  hoisting  cable  with  ropes  before  it  is  removed  from  the 
skip  or  cage.  The  entire  operation  of  changing  from  skip  to  cages  or  vice 
versa  is  quickly  performed  by  a  man  stationed  at  the  platform  in  the  headframe 
where  are  situated  the  levers  for  operating  the  air  cylinders  that  control  the 
swing  of  the  guide  and  for  throwing  out  the  lugs  to  engage  the  guide. 

Crane  for  Changing  Skips.— At  mines  where  hoisting  is  done  in  skips  it 
is  advisable,  and  sometimes  necessary,  to  have  a  special  cage  for  lowering 
and  hoisting  men.  At  the  Burra  Burra  mine  of  the  Tennessee  Copper  Co., 
Ducktown,  Tenn.,  cages  are  interchanged  and  made  ready  for  lowering  in  from 
30  to  60  seconds.  A  similar  arrangement  was  successfully  used  for  a  num- 
ber of  years  at  the  famous  Gwin  mine  on  the  Mother  Lode  of  California.  The 
changing  device  consists  of  two  cranes  at  the  shaft  mouth,  one  to  handle  each 
skip.  The  cranes  are  made  up  of  iron-pipe  verticals  with  channel-iron  swinging 
arms  stayed  from  the  top  of  the  uprights.  The  swinging  arms  carry  small  travel- 
ing crawls  to  which  are  attached  the  chains  by  which  the  skips  are  lifted.  The 
cranes  are  connected  across  the  top  and  are  also  stayed  in  several  directions  with 
wire  cables.  The  chains  can  be  attached  to  the  skips  by  slipping  the  hooks  at 
their  ends  into  eyes  which  are  provided  on  both  the  man  and  ore  skips. 

The  operation  of  changing  the  skips  is  as  follows:  When  a  skip  is  raised  to 
the  surface  the  chains  are  attached  to  it,  the  cable  secured  (as  will  later  be  ex- 
plained) ,  the  thimble  removed  and  the  skip  then  swung  out  of  the  way  by  a  rope 
attached  to  the  arm  of  the  crane;  the  other  skip  is  then  swung  in  from  the  other 
crane,  the  cable  attached  to  it,  chains  knocked  loose,  cable  made  free,  and  it  is 
ready  to  lower.  A  small  winch  is  provided  on  the  headframe  above  the  shaft's 
mouth.  When  skips  are  to  be  changed,  a  couple  of  men  must  stand  ready  at 
this  winch  in  order  to  fasten  the  cable  so  that  there  will  be  no  danger  of  its  being 
pulled  over  the  sheaves.  A  hitch  is  thrown  about  the  cable  with  a  piece  of  rope 
secured  to  and  drawn  taut  by  the  winch.  As  stated,  the  whole  operation  of 
changing  skips  occupies  only  about  a  minute,  and  from  the  added  security 


268 


HANDBOOK  OF  MINING  DETAILS 


obtained  in   raising  and  lowering  employees,  the  small  cost  of  installation  is 
certainly  warranted. 

Self  Acting  Tipple. — In  Figs  184  and  185  are  shown  the  details  of  a  satis- 
factory self-acting  tipple  which  was  developed  in  the  Birmingham  district  and  is 
used  by  the  Sulphur  Mining  &  R.  R.  Co.  at  its  mine  near  Mineral,  Louisa 
county,  Va.  The  loaded  ore  car  is  run  by  gravity  on  the  tipple  where  the  curved 


3  Rivets 


3  Rivets 


Side  View 
FIG.    184. — ARRANGEMENT   OF   TRACK   FOR  TIPPLE. 

3X3-in.  irons  a  engage  the  wheels.  The  tipple  is  so  designed  that  the  weight 
of  the  loaded  car  is  sufficient  to  cause  it  to  rotate  about  the  axis  b,  and  hence 
dump  the  car.  It  is  also  heavy  enough  to  swing  back  into  position  after  dumping 
with  sufficient  force  to  run  the  car  off  the  tipple  and  back  on  the  track.  A  wheel 
and  band  brake  may  be  used  on  axis  b  at  A ,  but  this  is  not  necessary.  This  form 
of  tipple  is  simple  in  operation,  easily  constructed  and  gives  good  service. 


FIG.    185. — AUTOMATIC   TIPPLE    WITH   SUPPORT. 

The  Republic  and  Tennessee  companies,  in  their  newer  slopes  on  Red 
Mountain,  Ala.,  hoist  in  lo-ton  skips  which,  in  headings  are  filled  from  2-ton 
cars,  dumped  by  tipples  directly  into  the  skips.  The  details  of  the  tipples  used 
in  headings  by  the  Tennessee  Coal,  Iron  &  R.  R.  Co.,  are  shown  in  Fig.  186. 
The  cars  are  strong  and  simple  in  construction.  They  are  made  of  3/8-in. 
steel,  braced  and  reinforced  as  shown.  By  having  the  body  of  the  car  low  and 
long,  2  ft.  4  in.  X  6  ft.  6  in.,  several  advantages  are  gained.  In  the  first  place 
the  cars  are  easy  to  load,  which  is  an  important  consideration.  This  construc- 
tion, on  account  of  the  low  center  of  gravity,  also  adds  stability  and  reduces  the 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


269 


liability  of  the  car  to  overturn  or  jump  the  track;  at  the  same  time  the  long  body 
does  not  make  tipping  excessively  difficult.  The  low  body  also  allows  the  dump 
end  of  the  car  to  be  hung  6  in.  above  the  side,  thus  giving  an  opening  sufficiently 
wide  to  allow  the  ore  an  easy  passage  from  the  car.  The  illustration  shows  the 
car  in  the  tipple  in  position  of  dumping  the  extra  clearance  gained  by  having 
the  movable  end  hung  above  the  sides  of  the  car  being  brought  out  by  the  dotted 
lines. 


Side  Elevation  of  Car 


f       End  Elevation       ' 
S          of  Cir            f 

I 

I 

-7 

1 

lo|           ,          jo 

I 

^_J  _jj  L 

jL    It  If 

V 


tqn^ 

Bottom  View  of  Car 


~r~r 


»j 

,r- 
T 

14 


...„••  i.N 


Section  and 
Plan  of  Tipple 


Square 


Scale. 
FIG.    l86. — CONSTRUCTIONAL  DETAILS   OF  CARS  AND   TIPPLES. 

The  tipple  is  of  simple  construction,  being  built  of  pieces  of  4o-lb.  track  rail 
curved  back,  so  as  to  grip  the  wheels  of  the  car,  and  cross-braced  with  a  3X  5/8- 
in.  iron  at  the  track  end,  and  a  2  i/2X  5/8-in.  iron  on  the  curve,  7  in.  above  its 
base.  A  lateral  brace,  2X1  in.,  connects  these  cross-braces  and  it  is  twisted  at 
the  center  so  that  it  may  be  riveted  to  pieces  of  similar  material,  with  the 


270 


HANDBOOK  OF  MINING  DETAILS 


larger  dimension  placed  vertically.     A  piece  of  2  1/2X2  i/2-in.  iron  is  used 
for  the  axle,  8  in.  being  allowed  at  either  end  for  bearing. 

Tram  Car  Tipple  (By  Guy  C.  Stoltz).— A  tram-car  tipple  used  by  the 
Cheever  Iron  Ore  Co.,  and  Witherbee,  Sherman  &  Co.,  in  the  Mineville,  N.  Y., 
iron  district,  is  similar  in  principle  to  the  one  described  above.  A  distinctive 
feature  in  this  tipple,  however,  is  the  bumping-block  arrangement  which  is 
attached  to  the  frame  proper  as  shown  in  Fig.  187.  The  tipple  is  made  of  8X  8- 
in.  timbers,  securely  tied  together  and  operating  on  a  frame  of  8X  8-in.  timbers. 
As  the  car  assumes  a  position  of  45°  in  discharging  its  contents,  the  back  of  the 


Bumping  Block. 
2  Spiral  Springs 


FIG.    187. — TIPPLE   USED    BY   WITHERBEE,    SHERMAN   &    CO.,    MINEVILLE,    N.    Y. 

car  strikes  against  a  bumping  block,  which  has  behind  it,  two  spiral  springs 
which  contract  3  in.  before  the  block  will  press  against  a  secondary  bumper. 
This  device  lessens  the  shock  to  the  tipple  and  frame  in  dumping  and  makes  a 
saving  on  tram-car  repair  bills.  The  axle  is  in  such  a  position  with  respect  to 
the  center  of  gravity  of  the  car  and  tipple,  that  a  tram  car  will  automatically 
dump  when  pushed  on  the  tipple  at  the  average  rate  a  man  walks. 

Revolving  Tipple. — The  revolving  tipple  for  mine  cars  has  the  advantage 
that  it  simplifies  the  construction  of  the  car.  It  saves  a  large  number  of  castings 
and  no  hinges  are  necessary.  The  car  can  be  made  much  lighter  on  this 
account — simply  a  sheet-iron  box  mounted  upon  wheels.  The  tipple  may  be 
made  any  size,  but  a  convenient  one  for  a  car  that  one  man  can  handle  is  50  in. 
in  diameter  and  6  ft.  long.  The  two  rings  are  made  of  3/4X4-in.  steel  bars, 
held  together  by  3 -in.  angle  irons  at  the  top  which  engage  the  top  of  the  car. 
The  ends  of  the  angle  iron  are  split  and  bent  back  on  the  ring  and  fastened. 


SKIPS,  CAGES,  CARS  AND  BUCKETS 


271 


Rails  are  fastened  in  the  bottom  of  the  ring  as  shown  in  Fig.  188.  The  track  is 
24-in.  gage  and  the  entire  frame  is  mounted  upon  four  ordinary  car  wheels,  two 
at  each  end.  With  the  loaded  cars  the  center  of  gravity  is  above  the  center  of 
the  circle  and  the  car  is  practically  self  dumping.  When  the  car  has  been 


FIG.    l88. — REVOLVING   TIPPLE   FOR   ORE   CARS. 

emptied,  the  center  of  gravity  is  below  the  center  of  the  circle  and  the  car  again 
returns  to  its  original  position. 

Automatic  Trip  for  Ore  Cars. — The  automatic  tripping  device  shown  in 
Fig.  189  is  used  in  several  mines  at  Iron  Mountain,  Mich.     By  means  of  this 


— 3  Ft. 


FIG.    189. — CAR   WITH  AUTOMATIC   TRIP. 

device  it  is  possible  to  dump  one  car  on  any  one  of  three  piles.  This  is  accom- 
plished by  a  lever  d  in  front  of  the  car,  which  may  be  set  in  three  different 
positions.  Beneath  the  car  is  a  small  wheel  which  strikes  a  jack  j,  set  between 


272  HANDBOOK  OF  MINING  DETAILS 

the  rails  at  any  required  position  on  the  stockpile.  As  the  wheel  passes  over 
this  jack  it  is  lifted  and  the  catches  b,  which  hold  the  side  doors,  are  released 
and  the  doors  opened.  The  arm  of  the  catch  b  is  slotted  at  c  to  give  free  move- 
ment when  the  wheel  encounters  the  jack.  Similar  catches  are  operated  on  the 
other  end  of  the  car  by  a  connecting  rod  through  e.  One  jack  is  set  in  the  center 
of  the  track  and  the  wheel  strikes  this  when  the  lever  is  in  a  vertical  position. 
The  other  two  jacks  are  set  a  little  off  center  and  are  encountered  by  the  wheel 
when  the  lever  is  set  at  one  side.  The  car  tender  at  the  skips  sets  this  lever  for 
a  certain  stockpile  before  the  car  leaves  the  shaft.  During  the  winter  months, 
100,000  tons  of  ore  are  handled  per  month  in  this  way  from  a  single  shaft.  At 
the  Pewabic  mine  a  similar  car  is  used  for  sending  ore  to  the  various  bins,  but 
instead  of  the  automatic  trip  being  changeable  the  side-dump  car  has  a  movable 
bottom  a,  extending  from  the  center  to  the  top  so  as  to  deliver  the  ore  on  either 
side  of  the  car,  but  not  on  both  sides  at  once. 


SAFETY  APPLIANCES 

Hooks  and  Thimbles — Crossheads  and  Safety  Catches — Landing 

Chairs,  Shaft  Gates  and  Other  Appliances— Notes  on 

Mine  Track  and  Switches. 

HOOKS  AND   THIMBLES 

Hoisting-bucket  Hooks. — The  greater  part  of  the  ore  produced  by  the 
Joplin  mines  is  raised  to  the  surface  in  buckets  of  800  to  850  Ib.  capacity. 
These  buckets  are  raised  at  such  a  speed  that  a  round  trip  from  a  depth  of  250 
ft.  is  made  in  35  seconds.  To  maintain  hoisting  at  this  speed,  a  hook  must  be 
used  on  the  hoisting  rope  that  will  permit  the  hooking  and  unhooking  of 
buckets  with  the  utmost  facility.  Snap  and  "pig-tail"  hooks,  as  shown  in  Fig. 


FIG. 


SNAP  AND   PIG-TAIL  BUCKET  HOOKS 
USED   IX    JOPLIN   MINES. 


FIG.    IQI. — SWIVEL  HOOK  FOR 
HOISTING. 


190,  are  used,  the  former  being  considered  safer.  The  snap  hook  is  made 
of  i  i/4-in.  steel  and  the  snap  is  held  in  a  groove  in  the  point  of  the  hook  by  a 
coiled  spring  that  is  housed  in  the  sheath  welded  to  the  shank  of  the  hook.  The 
pig- tail  hook  is  made  of  i  i/4-in.  iron,  bent  in  a  spiral  4  in.  in  diameter  and  of 
18  273 


274  HANDBOOK  OF  MINING  DETAILS 

2-in.  pitch,  which  permits  easy  entrance  of  the  i  i/4-in.  bail  of  the  bucket. 
Both  the  snap  hook  and  the  pig-tail  hook  are  attached  to  the  Jioisting  rope  by  a 
swivel.  By  constructing  the  hook  with  ball  bearings  in  the  swivel  joint  as 
shown  at  K  in  Fig.  191,  twisting  of  the  cable  is  not  communicated  to  the  bucket. 
A  Safety  Hook  for  Hoists. — A  patent  was  recently  granted  in  Great  Britain 
for  the  safety  hook  shown  in  Fig.  192,  the  operation  of  which  is  apparent.  The 
opening  of  the  hook  is  closed  by  the  simple  lever  A ,  one  end  of  which  is  attached 
to  the  sliding  member  B  as  shown.  W  hen  the  rope  is  slack  the  sliding  member 
slips  to  its  low  position  opening  the  hook  by  raising  the  end  of  the  lever  A .  Upon 
taking  up  the  slack  of  the  hoisting  rope,  the  hook  opening  is  closed  by  the  lever. 


FIG.    192. — A    SELF-LOCKING   HOIST  HOOK. 

The  pull  of  the  rope  does  not  come  on  the  pin  C,  but  upon  the  part  E  of  the  body 
of  the  hook  D,  a  projection  F  of  the  sliding  member  engaging  the  part  E  of  the 
body. 

Safety  Crane  Hooks. — Three  safety  hooks  in  use  in  the  works  of  the  Na- 
tional Tube  Co.  are  shown  in  Fig.  193.  A  safety  hook  having  a  lock  or  safety 
piece  which  closes  the  entrance  to  the  hook  when  in  place,  and  is  held  from 
opening  by  the  sliding  collar  on  the  shank  of  the  hook,  is  shown  at  A.  When 
the  safety  locking  device  has  closed  the  entrance  and  the  collar  has  dropped  into 
the  notch,  it  is  practically  impossible  for  the  sling  to  get  away.  If  the  latch  is  not 
in  place  and  the  hook  made  safe,  the  collar  will  not  fall.  When  the  collar  has 
fallen  into  place,  the  sling  cannot  come  out  of  the  hook  except  by  exerting  a 
force  sufficient  to  bend  and  displace  the  latch.  At  B  is  shown  a  form  of  toggle 
hook  for  use  in  lifting  large  plates.  The  sister  hooks  were  formerly  forged  in  one 
piece  and  the  weight  of  the  plate  was  depended  upon  to  jam  the  jaws  so  tightly 


SAFETY  APPLIANCES 


275 


by  friction  that  the  plate  was  not  likely  to  slip  out  and  hurt  anyone.  In  the 
modification  and  improvement  shown  in  the  cut,  it  will  be  apparent  that  the  end 
of  the  flat  link  can  be  forged  with  the  hole  eccentric  to  the  curve  of  the  end,  so 
that  when  the  strain  comes,  the  bite  of  the  cam  will  be  the  stronger  upon  the 
plate  he  heavier  the  applied  load.  It  is  practically  impossible  for  such  a  hook 
to  slip  off  as  long  as  the  weight  of  the  plate  is  borne  upon  the  suspending  chain. 
At  C  is  shown  a  crane  hook  with  a  handle  for  guidance,  as  used  in  some  of  the 
western  smelteries.  By  using  the  handle  the  operator  is  in  no  danger  of  having 
his  hand  caught  while  holding  the  hook  in  place  until  the  chain  to  which  it  is 
attached  has  been  drawn  taut. 


FIG.    193. — TYPES    OF   SAFETY   CRANE  HOOKS. 

Details  of  a  patented  self-closing  safety  shackle  hook  for  hoisting  work  are 
shown  in  Fig.  194.  There  have  been  many  accidents  due  to  the  disengaging  of 
ropes  and  chains  from  hooks  and  shackles,  and  this  device  aims  at  their  pre- 
vention. As  shown  in  Fig.  i,  A  represents  the  attaching  member;  B  the  hook 
member.  The  attaching  portion  is  formed  with  an  eye  C.  A  pivot  bolt  H  is 
passed  through  the  attaching  member  and  the  hook  member  to  secure  the  two 
parts  together.  This  pivot  bolt  is  arranged  a  little  to  one  side  of  where  the  line 
of  load  falls  on  the  hook.  When  there  is  a  pull  simultaneously  on  the  eye  and 
hook,  it  will  force  the  hook  tightly  against  the  guard-finger  D,  and  the  harder  the 
pull  the  more  the  hook  member  will  be  sustained  by  the  pressure  of  the  guard- 
finger  against  the  end  of  the  hook,  thus  preventing  to  a  considerable  degree 
any  chance  of  straightening  out  the  hook  under  a  heavy  load.  From  the  lower 
end  of  the  attaching  member  there  is  a  heavy  inward  thrust  against  the  lower 
end  of  the  hook  member  when  a  load  is  applied,  which  together  with  lug  E 
greatly  strengthens  the  hook.  It  is  claimed  that  a  hook  made  in  this  manner, 
of  good  material,  should  be  safe,  handy  and  stronger  than  an  ordinary  open  hook 
as  the  stress  is  transmitted  to  all  parts;  that  it  is  useful  for  all  kinds  of  hoisting 
work  where  ordinary  hooks  are  not  to  be  relied  upon,  and  particularly  where 
shackles  are  used  and  quick  changes  are  required.  In  using  shackles  sometimes 
the  pin  is  carelessly  or  incompletely  inserted,  sometimes  resulting  in  serious 


276 


HANDBOOK  OF  MINING  DETAILS 


accidents.  This  danger  is  obviated  by  the  use  of  a  hook  of  this  kind  because  as 
long  as  the  weight  is  on  the  hook  it  cannot  open,  but  for  still  further  security, 
a  cotter  pin  can  be  inserted  in  the  hole  formed  in  the  lug  I  if  desired.  This  hook 
has  been  indorsed  by  the  leading  casualty  companies  and  the  American  Museum 
of  Safety,  after  a  thorough  investigation.  It  is  the  invention  of  F.  F.  Norden, 
and  is  being  used  and  placed  on  the  market  by  the  Foundation  Co.  of  New  York. 


FIG.  2. 

FIG.    /  Back  View. 

4.     FIG.  3.  Upper  Member. 
View  as  in  Fig.  2  with 
Lower  Member  removed.  FIG.  5. 

FIG.    194. — A   NEW   SAFETY   CRANE  HOOK. 

Thimble  for  Hoisting  Cable. — In  hoisting  the  zo-ton  skips  used  in  the 
slopes  of  the  Tennessee  Coal,  Iron  &  R.  R.  Co.  on  Red  Mountain,  Alabama, 
much  difficulty  was  experienced  in  fixing  the  wire  rope  to  the  bails  of  the  skips 
so  that  they  would  not  pull  out.  The  pull  exerted  by  the  hoisting  engines  is  so 
great  that  ordinary  clamps  will  not  hold  at  all.  This  trouble  has  been  over- 
come by  using  thimbles  of  the  type  shown  in  Fig.  195.  The  eye-piece  a,  through 
which  the  bail  of  the  skip  passes,  is  keyed  to  the  main  shank  b  of  the  thimble  by 
two  square  lugs  d.  The  clamps  e,  which  are  drawn  down  on  the  cable  by  the 
bolts  g,  hold  the  keys  in  place.  The  clamps /are  similar  to  the  larger  ones  and 
are  bolted  in  the  same  fashion.  The  thimble  is  fitted  to  the  skip  bail  by  re- 
moving the  larger  clamps,  thus  releasing  the  eye-piece  which  is  placed  about  the 
bale,  the  key  lugs  and  clamps  then  being  replaced.  The  hoisting  cable  passes 
under  clamp/,  under  e,  around  a  and  then  back  under  the  opposite  ends  of  e  and 


SAFETY  APPLIANCES 


277 


/;  b  and  a  are  grooved  to  receive  the  rope  as  shown  in  the  sectional  views.  Fi- 
nally the  clamps  are  drawn  down  upon  the  cable  by  the  bolts  upon  which  lock 
nuts  are  used.  Usually  several  ordinary  clamps  are  used  to  hold  the  loose  end 
of  the  rope  to  the  taut  end. 


Section  A-A 


FIG.    195. — DETAILS   OF  HOISTING-CABLE   THIMBLE. 


CROSSHEADS  AND  SAFETY  CATCHES 

Safety  Crossheads  for  Hoisting  Buckets. — Because  accidents  have  been 
caused  by  the  falling  of  crossheads  in  shafts,  the  Ontario  Bureau  of  Mines  calls 
attention  in  its  report  for  the  year  1911  to  the  safety  crossheads  that  have  been 
designed  and  patented  by  Mr.  Morin,  master  mechanic  at  the  Nipissing  and  Mr. 
Sargeson,  master  mechanic  at  the  Waldman  mine.  The  object  of  the  design 
of  these  crossheads  is  to  prevent  them  from  falling  when  they  stick  in  the  shaft. 
In  the  Sargeson  crosshead,  which  is  shown  in  Fig.  196,  the  attachment  A  is  fast- 
ened to  the  crosshead  at  C.  If  the  crosshead  sticks,  this  arm  automatically 
engages  the  clip  B,  attached  to  the  cable,  and  so  stops  the  bucket.  In  sinking 
operations  the  arm  A  is  automatically  tripped  by  the  stop  block  E,  allowing 
the  bucket  to  descend  to  the  bottom  of  the  shaft.  In  Fig.  196,  A  shows  the 
the  attachment  in  normal  position;  7,  the  attachment  tripped  by  the  crosshead 
stop;  B,  the  clip  in  normal  position;  /,  the  clip  lowered  through  the  tripped 
attachment;  C,  the  daw  pin;  D,  the  cable;  E,  the  crosshead  stops;  F,  the 
guides;  and  H,  the  crosshead. 

The  same  principle  is  followed  in  the  design  of  the  Morin  crosshead.  It  is 
further  equipped  with  an  automatic  safety  device,  which  by  the  aid  of  springs 
enables  dogs  to  grip  the  guides,  thus  preventing  the  crosshead  from  falling. 

Safety  Crossheads  for  Hoisting  Bucket  Shaft.— A  crosshead  is  in  use 
at  the  Colby  mine  at  Bessemer,  Mich.,  which  holds  the  bucket  whenever  the 
crosshead  is  stopped  either  accidentally  or  intentionally.  C.  E.  Holley  describes 


278 


HANDBOOK  OF  MINING  DETAILS 


the  device  as  follows:  At  a  suitable  distance  above  the  bucket,  the  thimble 
shown  in  Fig.  197  is  attached  to  the  cable  by  U-bolts.  The  crosshead  is  made 
up  of  channels  bolted  to  vertical  timbers.  Across  the  bottom  channels  is  a 
yoke  Y  through  which  the  cable  passes,  and  this  yoke  rests  on  the  top  of  the 
thimble,  thus  supporting  the  crosshead.  The  dogs  D  close  in  below  the  collar 
of  the  thimble  preventing  the  bucket  leaving  the  crosshead  in  case  the  crosshead 
should  stick  in  the  shaft  while  being  lowered.  When  the  crosshead  strikes  the 
stop  at  the  bottom  of  the  guides,  the  lever  L  is  raised,  raising  the  wedge  W. 
This  wedge  forces  the  dogs  apart  and  permits  the  thimble  to  pass  down  be- 


no.    196. — SAFETY  CROSSHEAD   USED  AT  A   COBALT   MINE. 

tween  them,  lowering  the  bucket  without  the  crosshead.     The  wedge  is  guided 
by  an  extension,  which  slides  in  a  hole  in  the  yoke. 

The  details  of  the  crosshead  used  in  sinking  the  Morning  shaft,  at  the  Federal 
Mining  &  Smelting  Co.'s  mine,  near  Mullan  Ida.,  are  shown  in  Fig.  198.  The 
design  is  satisfactory,  being  the  result  of  several  experiments  made  by  the  com- 
pany along  this  line.  One  great  advantage  of  such  a  crosshead  is  in  its  lightness. 
One  man  can  handle  it  when  necessary.  At  the  same  time  it  is  strong,  sure  in 
action  and  of  simple  construction.  The  main  frame  of  the  crosshead  is  built 
up  of  members  constructed  of  two  angle  irons.  The  verticals  are  2X  2X  i/4-in. 
angles,  6  ft.  long  and  set  21/16  in.  from  each  other.  The  guide  shoes  A ,  spaced 
3  ft.  10  in.  apart,  are  riveted  to  a  filler  plate  and  the  angles.  The  shoes  are  1/4 
in.  wider  than  the  guides,  which  are  5X  6  in.  The  top  and  bottom  members  of 
the  frame  are  made  up  of  two  2  1/2X2  i/2X5/i6-in.  angle  irons.  A  3/8-in. 


SAFETY  APPLIANCES 
Detail  of  Thimble 


279 


-•    FIG.    197. SAFETY   CROSSHEAD    FOR  HOISTING    BUCKETS. 


FIG.    198. — CROSSHEAD   USED   ON   SINKING  BUCKET   IN   MORNING  MINE. 


280 


HANDBOOK  OF  MINING  DETAILS 


cover  plate  is  used  on  the  upper  member.  At  a  point  slightly  below  its  center 
the  frame  is  cross-braced  with  two  angle  irons.  In  the  lower  half  i/4X2-in. 
diagonal  braces  are  used  to  stiffen  the  frame.  The  center  rod  B,  to  which  the 
hoisting  cable  is  fastened,  is  made  of  i  i/4-in.  material.  A  spring  C,  4  in.  in 
diameter,  made  of  ;/  i6-in.  wire,  22  1/2  in.  long,  is  coiled  about  the  rod  and  bears 
up  against  a  disk  on  the  lower  side  of  the  central  cross-brace  of  the  frame.  A 
clamp  on  the  rod  bears  on  the  lower  end  of  the  spring.  This  clamp  is  connected 
by  i/2-in.  rods  D  to  the  dogs  E.  There  are  three  points  at  which  the  connecting 
rods  may  be  joined  to  the  dogs.  The  proper  adjustment  may  thus  be  obtained. 
There  are  two  other  clamps  on  the  central  rod  which  prevent  the  spring  from 
being  compressed  beyond  its  limit  by  coming  up  against  the  horizontal  members 
of  the  frame.  The  bucket  is  suspended  from  the  crosshead  by  two  chains. 

By  using  a  crosshead  with  a  sinking  bucket,  much  time  can  be  saved.  How- 
ever, the  additional  safety  afforded  the  men  while  riding  the  bucket,  should  be 
sufficient  consideration  to  warrant  the  necessary  expense  for  the  installation. 
The  bucket  being  suspended  by  comparatively  short  chains  from  two  points 
instead  of  one,  the  tendency  to  twist  and  swing  while  it  is  being  lowered  or  hoisted 
is  much  reduced.  This,  of  course,  makes  riding  the  bucket  safer  and  enables 
hoisting  to  be  carried  on  at  a  greater  speed  than  is  permissible  without  the  use 
of  a  crosshead. 

The  Bryant  Safety  Crosshead. — In  Fig.  199  is  illustrated  a  safety  cross- 
head  for  use  in  shaft  sinking  that  has  been  patented  by  Thomas  Bryant  of  Butte, 


M 


FIG.    199. — BRYANT   SAFETY   CROSSHEAD. 

Mont.  A  crosshead  of  approximately  this  type  was  installed  at  the  Original 
Consolidated  mine  in  that  district.  The  frame  of  the  crosshead  comprises, 
upper  and  lower  cross-bars  A,  platform  B,  braces  C  and  side  arms  D,  which  are 
provided  with  guide  shoes  E.  The  cross-bars  are  provided  with  the  central 
passages  G.  The  skip,  cage,  or  bucket  is  secured  to  the  rope  or  cable  by  a 
shackle  /,  having  a  head  K  which  normally  engages  the  bottom  of  the  lower 


SAFETY  APPLIANCES  281 

cross-bar.  A  tube  or  sheath  L  incloses  the  lower  portion  of  the  rope  and  is 
movably  mounted  on  the  cross-bars  in  the  passages  G.  Normally  this  sheath 
rests  upon  and  is  supported  by  the  head  K  of  the  shackle,  but  when  the  sup- 
port is  withdrawn,  downward  movement  is  limited  by  a  collar  M.  The  upper 
part  of  the  sheath  projects  a  short  distance  above  the  upper  cross-bar  and  has 
chains  N  secured  at  the  opposite  sides  of  the  collar  M.  Each  chain  is  connected 
with  a  sheave  P  keyed  to  a  shaft  Q.  One  or  more  springs  S  are  secured  to  each 
shaft  so  they  will  normally  operate  to  wind  the  chains  upon  the  sheaves.  The 
dogs  T  are  rigidly  fastened  to  each  shaft. 

When  the  crosshead  is  operating  in  its  usual  manner  it  rests  upon  the  shackle 
and  moves  up  and  down  upon  the  guides  with  the  rope.  The  sheath  L  is  held 
in  its  raised  position  and  pulling  upon  the  chains  N  holds  the  dogs  T  in 
their  nonoperative  position  against  the  tension  of  the  springs  S.  When  the 
crosshead  strikes  any  obstruction  or  sticks  accidentally  while  the  cable  is  de- 
scending, the  rope  with  the  carrier  attached  will  continue  its  downward  move- 
ment independently  of  the  crosshead.  The  shackle  disengages  from  the  lower 
end  of  the  sheath  which  thereupon  drops  by  gravity,  and  under  the  tension  of 
the  springs,  into  its  lowermost  position;  simultaneously  the  springs  rotate  the 
shafts  to  bring  the  teeth  on  the  dogs  into  engagement  with  the  guides.  The 
crosshead  will  thus  be  securely  held  until  the  bucket  is  raised  again  and  the 
cable  engages  with  and  raises  the  tube,  thereby  rotating  the  shafts  Q  by  means  of 
the  chains  and  returning  the  dogs  to  their  nonoperative  position. 

By  this  construction  the  disasters  caused  by  the  falling  of  the  crosshead  upon 
the  bucket,  after  being  accidentally  caught  on  the  guides,  are  effectually  pre- 
vented. At  the  same  time  the  cable  is  always  free  to  move  independently  of  the 
crosshead  and  if  the  crosshead  should  be  caught  no  delay  is  occasioned  as  the 
cable  can  be  lowered  as  far  as  desired  and  then  when  raised  again  the  crosshead 
will  be  automatically  released.  In  case  the  traction  cable  breaks  it  is  obvious 
that  the  safety  means  will  operate  automatically  in  the  same  manner  as  when 
the  crosshead  is  accidentally  caught  and  will  prevent  the  crosshead  from  falling 
to  the  bottom  of  the  shaft.  The  mechanism  is  especially  adapted  for  use  in 
shaft  sinking  in  places  where  it  is  necessary  to  lower  the  bucket  below  the  end  of 
the  guides,  since  a  stop  or  other  obstruction  placed  at  the  ends  of  the  guides 
will  cause  the  safety  device  to  operate  and  hold  the  crosshead  positively  and 
independently  while  the  bucket  is  lowered  to  the  bottom. 

An  improvement  of  the  Bryant  crosshead,  shown  in  Fig.  200,  consists  in  a 
safety  device  for  preventing  the  falling  of  the  bucket  in  case  of  the  breaking  of 
the  hoisting  rope.  In  the  illustration  the  bucket  A  is  shown  suspended  below 
the  cage  B  by  the  hoisting  rope  C  which  passes  through  a  hollow  shaft  D  set 
vertically  in  the  cage.  The  end  of  the  hoisting  rope  terminates  in  a  shackle  with 
collar  E,  the  collar  of  which  engages  and  holds  the  bottom  of  the  cage  so  as  to 
carry  the  cage ;  the  point  of  support  being  at  the  bottom  instead  of  the  rope  being 
attached  at  the  top.  A  chain  F  is  suspended  from  the  hoisting-rope  shackle, 


282 


HANDBOOK  OF  MINING  DETAILS 


which  carries  the  bucket  as  shown.  This  chain  carries  a  circular  disk  G,  which 
is  dished  so  that  the  edge  fits  into  and  engages  the  hooked  ends  of  the  two  bell- 
crank  levers  H  which  are  pivotally  supported  from  the  lugs  7  dependent  from 
the  bottom  of  the  cage. 

To  any  part  of  the  guides,  at  a  point  below  which  it  is  not  desired  that  the 
cage  should  pass  but  below  which  the  bucket  is  to  be  used,  two  lugs  /  are 


FIG.    2OO. — DEVICE   FOR    LOWERING    BUCKET    INDEPENDENTLY    OF   CAGE. 


bolted.  These  engage  the  ends  of  the  bell-crank  levers  H  throwing  their 
other  ends  out  of  engagement  with  the  disk  G.  These  lugs  hold  the  cage  from 
sinking  but  the  bucket  may  be  lowered,  the  hoisting  rope  passing  freely  through 
the  hollow  vertical  shaft  in  the  cage.  The  hooks  and  disk  provide  safety  inas- 
much as  the  bucket  will  not  drop  from  the  bottom  of  the  cage  in  event  of  the 
breaking  of  the  hoisting  rope.  When  the  cage  is  resting  on  the  guide  lugs,  and 


SAFETY  APPLIANCES  283 

the  bucket  is  being  lowered,  the  safety  dogs  at  the  top  of  the  cage  are  released 
so  as  to  bite  into  the  wooden  guides  so  that,  in  case  the  lugs  should  break,  the 
cage  will  not  fall.  In  hoisting  the  bucket  the  rope  passes  freely  through  the 
hollow  shaft  in  the  cage  until  the  disk  is  at  a  point  above  the  hooks  of 
the  levers  H.  When  the  collar  E  comes  in  contact  with  the  bottom  of  the  cage, 
the  safety  dogs  are  released  and  the  cage  raised  together  with  the  bucket  where- 
upon the  bell-crank  levers  drop  into  position  so  as  to  engage  the  disk.  The 
device  is  patented. 

Safety  Catch  for  Cage  (By  H.  L.  Botsford). — Many  devices  have  been 
designed  to  prevent  accidents  to  mine  cages  from  the  breaking  of  the  hoisting 
rope.  They  may  all  be  divided  into  two  general  classes:  safety  stops,  and  safety 
brakes.  The  former  aim  to  stop  the  cage  instantly,  by  some  positive  means, 
such  as  the  slipping  of  bolts  into  holes  in  the  guide  timbers.  This  class  of 
safety  catch  would  be  satisfactory  if  the  cage  could  always  be  stopped  just 
at  the  instant  the  rope  broke,  on  an  ascending  cage,  and  before  the  cage  had 
acquired  any  appreciable  downward  velocity.  Should  the  catches  refuse  to 
work  until  the  cage  had  gained  considerable  momentum,  or  should  the  rope 
break  while  the  cage  was  descending,  and  the  speed  of  the  cage  should  not  be 
entirely  checked  before  the  hoisting  rope  failed,  the  stresses  produced  in  the 
safety  catches  would  be  too  severe  for  them  to  resist  successfully.  Even  should 
the  catches  be  able  to  stand  the  strain,  there  yet  would  be  great  danger  of  bodily 
harm  to  the  occupants  of  the  cage  from  the  shock  of  sudden  stoppage. 

These  serious  objections  to  the  safety  stops  are  not  so  inherent  in  the  second 
class  of  safety  catches.  Safety  brakes  are  designed  with  the  aim  to  arrest 
gradually  the  momentum  of  a  descending  cage,  without  danger  to  the  occupants 
of  the  cage,  or  to  the  safety-catch  mechanism.  In  one  type  of  safety  brake 
wedges  are  made  to  grip  the  guide  timbers,  when  there  is  no  tension  in  the  hoist- 
ing rope.  The  motion  of  the  descending  cage  forces  them  tighter  and  tighter 
against  the  guides  until  the  cage  is  stopped.  This  type  has  not  proved  satis- 
factory. In  a  second  type  of  safety  brake,  friction  shoes  are  forced  against  the 
guides  by  the  action  of  compressed  carbonic  acid  gas  against  plungers.  The  gas 
is  stored  in  cylinders  under  a  pressure  of  several  hundred  pounds  per  square 
inch.  This  type  has  given  good  service  at  the  mines  of  the  Rand.  It  may  be 
used  with  steel  guides.  In  a  third  type  of  safety  catch,  or  brake,  much  used  in 
America,  cams  or  "dogs"  are  made  to  engage  the  guides,  one  on  each  side  of 
each  guide.  These  cams  have  toothed  or  grooved  surfaces,  which  cut  into  the 
guide  timbers.  They  are  quicker  in  their  action  than  the  friction  blocks 
described  above,  although  they  may  properly  be  classed  with  safety  brakes 
because  their  action  is  to  stop  the  cage  by  the  resistance  which  they  meet  in 
deforming  or  cutting  the  guides.  Obviously  they  can  only  be  used  with  wooden 
guides. 

This  type  of  safety  catch  depends  for  its  action  upon  springs  which  force  the 
cams  against  the  guides  when  the  tension  in  the  hoisting  rope  is  released.  While 


284 


HANDBOOK  OF  MINING  DETAILS 


the  weight  of  the  cage  is  supported  by  the  hoisting  rope  the  cams  are  drawn  back 
from  the  guides,  and  in  no  way  interfere  with  the  free  running  of  the  cage. 

Much  variation  is  shown  in  the  design  of  cams,  and  in  the  choice  of  springs. 
The  springs  may  be  of  the  laminated,  spiral,  or  the  helical  type.  The  laminated 
spring  is  but  little  used.  In  many  mining  districts  one  type  of  cage  construction 
is  used  almost  exclusively. 

In  Fig.  201  a  cage  long  in  use  in  the  copper  country  of  Lake  Superior  is 
shown.  In  this  construction  the  cage  is  hung  by  two  hanger  forks  H  from  the 
drawbar  sleeve  G,  through  which  the  drawbar  A  is  free  to  slide.  While  the 


%-in.  Plate 


2% -in.  Ed. 


K-in.  Plate 


2M  x  X-ln. 
Strap 


1  x  5-in.  Plate 


Bolt 

Door  this  Side 

(not  shown) 

Same  as  Oppo- 

ite  .Side. 

Bushing. 


Sleeve  or  Guide 

for  Bottom  Bnd 

of  Drawbar 


Floor  ^-in.  Plate, 

Perforated  with 

2-in.  Holes. , 


Four  Supports 
for  Floor  Plate 


FIG.  2OI. — A  LAKE  SUPERIOR  TYPE  OF  MINE  CAGE  WITH  SAFETY  CATCH. 

cage  is  hanging  on  the  hoisting  rope  the  yoke  B  on  the  drawbar  carries  the  weight 
of  the  cage.  The  springs  F  have  one  end  fastened  to  the  side  plates  of  the  cage 
and  the  other  end  to  the  lever  E,  keyed  to  the  camshaft.  The  camshafts  are 
connected  to  the  yoke  B  by  the  lever  arms  D  and  the  chains  /.  If  the  chains  / 
are  of  the  proper  length,  the  cams  will  be  turned  back  from  the  guides,  when  the 
drawbar  is  raised  to  its  full  height,  that  is,  when  the  yoke  B  is  in  contact  with  the 
drawbar  sleeve  G.  This  is  the  position  the  drawbar  assumes  while  the  cage  is 
suspended  on  the  hoisting  rope.  The  springs  F  are  now  under  tension,  and 
should  the  hoisting  rope  break,  or  the  cage  be  rested  upon  landing  chairs,  these 


SAFETY  APPLIANCES  285 

springs  will  rotate  the  camshafts  sufficiently  to  bring  the  cams  into  contact  with 
the  shaft  guides.  Any  downward  movement  of  the  cage  will  now  force  the 
cams  into  the  guides,  until  they  meet  with  sufficient  resistance  to  support  the 
weight  of  the  cage.  The  lower  end  of  the  drawbar  passes  through  the  sleeve 
or  guide  K  which  prevents  it  from  binding  in  the  sleeve. 

The  design  of  the  cams  themselves  is  a  very  important  detail  in  cage  con- 
struction. They  should  be  so  shaped  that  when  they  once  come  in  contact  with 
the  guide  timbers,  any  downward  motion  of  the  cage  must  force  them  deeper 
and  deeper  into  the  guides.  As  to  the  relative  merits  of  cams  with  notched  or 
grooved  faces,  and  those  with  projecting  teeth,  much  may  be  said  in  favor  of 
each.  The  sharpened  teeth  will  be  more  certain  to  cut  into  the  guides  at  the 
start,  while  the  other  type  makes  a  stronger  construction. 

Regardless  of  the  type  of  cage,  the  safety  catches  should  be  tested  regularly 
at  least  once  each  month.  This  is  conveniently  done  by  hoisting  the  cage  a 
few  feet  above  the  collar  of  the  shaft,  and  suspending  it  there  by  a  hemp  rope 
fastened  to  a  convenient  timber  in  the  headframe.  The  hoisting  rope  should 
now  be  slackened  a  few  feet  and  the  hemp  rope  severed.  This  gives  the  cage  a 
free  drop  until  the  catches  work,  or  the  slack  in  the  hoisting  rope  is  taken  up. 
With  safety  catches  in  good  order  they  should  not  permit  the  cage  to  drop  more 
than  a  few  inches. 


LANDING  CHAIRS  AND  OTHER  APPLIANCES 

Skip  Chairs  at  Argonaut  Mine. — Few  mines  hoisting  in  skips  use  chairs 
in  the  shaft,  but  rather  rely  upon  the  engineer  to  stop  near  enough  to  the  proper 
point  for  loading.  In  hoisting  from  depth  the  stretch  or  give  of  the  hoisting 
cable  is  enough  to  cause  considerable  motion  of  the  skip  up  and  down  the  shaft, 
after  stopping  the  hoist.  Loading  while  the  skip  is  in  motion  is  bound  to  result 
in  the  spilling  of  a  considerable  amount  of  rock  down  the  shaft.  This  is  always 
dangerous  and  should  be  avoided.  In  the  Argonaut  mine  at  Jackson,  Amador 
County,  Calif.,  Superintendent  Ralph  S.  Rainsford  has  devised  a  simple  type 
of  skip  chair,  which  is  shown  in  Fig.  202.  At  the  loading  station  in  the  shaft 
there  is  a  rod  A  connected  by  a  shorter  lever  to  the  4  X  6-in.  post.  This  piece  is 
capped  at  its  end  with  iron  and  acts  as  a  buffer  upon  which  the  skip  rests  during 
loading,  as  is  shown  by  the  dotted  lines.  There  is  a  counterbalance  C,  made  of 
8X8  material,  connected  to  the  buffer;  this  serves  to  swing  the  chair  between  the 
shaft  timbers  and  clear  of  the  skip,  when  not  in  use.  As  shown  in  the  side  view, 
a  spring  connecting  the  buffer  and  shaft  wall  plate  is  also  used  to  assist  in  swing- 
ing the  chair  back.  Where  it  is  possible  to  use  a  sufficiently  heavy  counterbal- 
ance, the  spring  is  unnecessary.  Skip  chairs  of  this  design  are  easily  and  cheaply 
constructed  and  placed  in  the  shaft.  Their  use  is  certainly  made  worth  while 
from  the  time  saved  in  loading  (not  having  to  wait  for  the  skip  to  come  to  rest) 
and  the  added  security  afforded  men  working  at  lower  stations  in  the  shaft. 


286 


HANDBOOK  OF  MINING  DETAILS 


Landing  Chair  for  Skips  in  Inclines. — The  usual  form  of  chair  or  gate  that 
is  used  in  inclines  for  the  skips  to  rest  on  consists,  as  shown  in  Fig.  2 03  a,  of  a 
strong  piece  of  timber  bolted  to  the  ends  of  two  arms  that  are  equipped  with  a 
counterweight  to  lift  the  gate  out  of  the  way  as  soon  as  the  skip  is  lifted  from  the 
chair.  These  gates  are  carried  by  two  posts  in  the  incline,  and  from  the  end  of 
the  arm  that  carries  the  counterweight  a  chain  goes  to  the  station  floor  by  means 
of  which  the  chair  is  raised  so  as  to  catch  the  skip.  The  objection  to  this  kind 
of  chair  is  that  when  the  skip  is  lowered  heavily  on  the  chair  or  gate,  the  arms 
are  bent.  It  therefore  takes  considerable  time  to  repair  this  form  of  gate.  On 
this  account  a  gate  whereof  the  cross  piece  rests  loosely  in  hooked  carriers,  which 
was  devised  by  Capt.  Samuel  Richards,  is  used  at  the  South  Hecla  shafts  of  the 
Calumet  &  Hecla  company.  This  gate  has  a  three-armed  spider  at  one  end  and 


Top  View 

FIG.    2O2. — SKIP   CHAIRS    USED    IN   ARGONAUT   MINE,    JACKSON,    CALIF. 

a  two-arm  spider  at  the  other.  To  the  end  of  one  of  the  three  arms  is  connected 
by  a  hinged  joint  the  counterweight  that  lifts  the  cross  piece  out  of  the  way  of 
the  skip  as  soon  as  the  skip  is  lifted  off  the  gate.  To  the  arm  extending  out  in 
the  opposite  direction  is  connected  by  a  hinged  joint  the  hook  in  which  is  carried 
the  cross  piece  that  stops  the  skip,  while  to  the  third  arm,  which  is  at  right  angles 
to  the  other  two,  is  connected  the  chain  or  rod  that  extends  to  the  floor  of  the 
station,  by  means  of  which  the  gate  is  thrown  in  when  desired.  The  details 
are  shown  in  Fig.  203 b.  Owing  to  the  fact  that  the  hooks  that  carry  the  cross 
piece  are  loosely  connected  to  the  arms,  the  cross  piece  as  it  moves  up  or  down 
slides  along  the  top  side  of  the  two  posts  that  carry  the  spider.  Consequently, 
in  case  a  skip  conies  down  heavily  on  the  chair  or  gate,  only  the  cross  piece  can 
be  broken  as  it  rests  directly  against  the  two  posts.  A  new  gate  timber  can  be 


SAFETY  APPLIANCES 


287 


put  in  quickly  to  replace  a  broken  one.  Chairs  of  this  type  have  been  in  use 
in  the  South  Hecla  shafts  for  some  time,  and  now  this  type  of  gate  is  to  become 
standard  for  all  the  inclines  of  the  Calumet  &  Hecla  company. 

Emergency  Chairs  on  Headframe. — The  weak  point  of  many  safety 
devices  is  that  they  depend  upon  springs  for  their  action  when  the  cable  strain 
is  released.  In  mine  usage  joints  and  bearings  rust  and  the  springs  deteriorate, 
so  that  when  the  accident  finally  happens  the  mechanism  may  refuse  to  work. 


FIG.  203  a.  FIG.  203  b. 

BUFFER   BARS    FOR   INCLINE    SKIPWAYS. 

Further,  cables  are  frequently  broken  by  winding  the  cage  up  to  the  sheave,  and 
a  force  strong  enough  to  break  the  cable  is  generally  also  sufficient  to  bend  the 
rods  and  jam  the  moving  parts  of  the  safety  clutch.  Assurance  should  be 
made  doubly  sure  by  placing  a  set  of  chairs  in  the  headframe  so  that  when  the 
cage  is  pulled  to  the  sheave  the  chairs  will  be  about  6  in.  below  the  floor  of  the 
lowest  deck  (a  separate  set  for  each  deck  would  be  preferable).  Chairs  so  placed 
are  high  enough  above  the  collar  to  be  out  of  the  way  of  ordinary  work.  They 
are  always  held  in  the  shaft  by  weights  or  springs  and,  being  easy  of  access, 
are  kept  in  first-class  condition.  Then  when  an  accident  occurs,  if  the  dogs 
of  the  clutch  fail  to  work,  the  cage  cannot  fall  down  the  shaft. 

Testing  Safety  Devices  on  Mine  Cages. — At  practically  all  the  mines 
operated  by  the  Oliver  Iron  Mining  Co.  in  Minnesota  and  Michigan,  the  safety 
catches  on  the  man  cage  are  tested  at  least  once  every  month.  Fig.  204  shows 
the  device  that  is  used  to  test  the  cage.  By  using  this  the  time  of  making  the  test 


288 


HANDBOOK  OF  MINING  DETAILS 


is  reduced  to  only  a  few  minutes.  A  cable  is  tied  across  the  shaft  to  the  guides 
or  runners  about  30  ft.  above  the  ground,  to  which  is  fastened  a  6-ft.  cable  with 
a  loop  in  each  end.  The  lower  end  is  attached  to  the  top  of  the  device  at  A, 
Another  short  piece  of  cable  with  a  loop  in  either  end  is  used  to  connect  the 
tripper  with  the  cage.  The  clutches  B  are  drawn  together  by  pressing  down  on 


FIG.    204. — TRIPPING   DEVICE   USED   IN  TESTING   SAFETY  APPLIANCES   ON   CAGES. 

the  lever  C,  and  a  lock  pin  placed  in  as  shown.  This  is  to  insure  no  tripping 
until  all  arrangements  are  complete.  When  all  connections  are  made  the  main 
cable  is  given  5  or  6  ft.  of  slack,  all  of  which  is  drawn  to  the  cage  by  means  of  a 
small  block  and  tackle.  A  good  strong  timber  is  placed  across  the  top  of  the 
shaft  to  prevent  the  cage  from  dropping  too  far.  The  pin  is  then  taken  out 
and  by  means  of  a  long  rope,  attached  to  the  lever  C,  it  is  drawn  up  sufficiently 


SAFETY  APPLIANCES 


289 


to  separate  the  jaws  and  allow  the  piece  of  supporting  cable  to  drop  out.  At 
most  the  cage  can  only  drop  3  or  4  ft.  before  it  strikes  the  timber  across  the 
top  of  the  shaft.  In  most  cases  the  safety  dogs  will  catch  in  the  guide  within 
less  than  i  ft.  If  not,  something  is  wrong  and  the  difficulty  is  remedied. 

Cage  Landing  Chairs  (By  W.  F.  Boericke). — In  Fig.  205  a  simple  cage 
chair  is  shown,  together  with  the  " fingers"  used  for  throwing  the  chair  into 
position.  It  is,  of  course,  necessary  that  the  supports  A  and  B  of  the  chair 
should  be  out  of  the  way  as  the  cage  goes  up  and  down,  an  inch  clearance  on 


FIG.    205. — LANDING  CHAIRS   IN   SHAFT. 

either  side  is  therefore  provided.  The  supports  are  of  3Xio-in.  timber,  shod 
with  flat  iron,  and  reinforced  by  bands  of  steel  going  completely  around.  The 
tops  are  sloped  as  indicated,  to  provide  a  flat  supporting  surface  for  the  cage 
when  the  chairs  are  thrown  in.  The  supports  are  securely  hinged  to  the  cross 
timber,  and  work  with  little  friction.  The  fingers  are  made  of  2-in.  flat  iron, 
and  at  the  point  C  the  device  is  bolted  to  the  guide.  The  chair  should  be  of 
such  height  that  the  car  will  be  exactly  level  with  the  tracks  on  the  landing,  and 
roll  off  without  trouble. 

Improved  Landing  Chair. — An  admirable  type  of  landing  chair,  patterned 
after  one  in  use  for  some  years  at  several  German  mines,  is  installed  at  the  Doe 
Run  mines,  Flat  River,  Mo.  The  prime  feature  of  the  chair  is  that  it  obviates 
the  inconvenience  and  delay,  and  the  consequent  waste  of  time  and  power, 
attending  the  lifting  of  the  cage  from  its  supports  by  the  hoisting  engine  before 
lowering  as  is  necessary  with  the  usual  types  of  chairs.  The  details  of  construc- 
tion are  shown  in  the  drawings  given  in  Fig.  206.  The  upward  projecting  sides 
of  the  sole  plate  A ,  are  bored  to  receive  the  two  axles,  L  and  D.  To  the  former 
19 


290 


HANDBOOK  OF  MINING  DETAILS 


are  rigidly  attached  the  hand  lever  H,  and  the  short  lever  K.  On  the  shorter 
axle  D,  are  fastened  the  two  short  links  E  E,  through  the  ends  of  which  passes 
the  pin  B.  The  pin  B  also  passes  loosely  through  the  inner  end  of  the  chair 
piece  C,  and  through  the  link  F,  the  other  end  of  which  is  loosely  attached  to  the 
lever  K,  by  the  bolt  7.  The  under  side  of  C  slides  freely  on  the  pillow  block  X. 
The  axles L,  of  the  two  mechanisms  on  the  opposite  sides  of  the  shaft  collar  are 
connected  by  keyed  levers  and  link  rods,  so  that  they  work  in  unison.  The 
principal  dimensions  are  as  follows:  L,  2  7/16  in.  in  diameter;  D,  2  7/16  in.;  B, 
2  1/8  in.;  I,  i  1/2  in.;  center  to  center, L-I,  3  -1/2  in.;  7-7?,  4  1/2  m.;B-D,  4  1/4 
in.;  length  of  D,  nine  inches. 


FIG.    2O6. — LANDING   CHAIR   USED   AT   FLAT   RIVER,    MO. 

The  essential  feature  of  the  design  is  that  when  the  weight  of  the  cage  is 
resting  on  the  outward  end  of  the  block  C,  the  latter  is  held  firmly  in  position 
by  this  weight;  it  cannot  tip  because  the  links  E  E  lie  in  a  vertical  line  from  B  to 
D,  and  it  cannot  slide  backward  because  the  link  F,  and  the  lever  K,  also  lie  in 
a  straight  line  from  B  to  L.  In  order  to  prevent  a  downward  motion  of  the 
joint  7,  due  to  the  weight  of  the  hand  lever  H,  a  block  M,  is  placed  below  the 
lever,  K,  to  stop  it  at  the  horizontal  position.  When  the  hand  lever  is  thrown 
backward,  through  an  angle  of  60°,  the  piece  C,  is  obviously  withdrawn,  and 
takes  the  position  shown  in  Fig.  2.  After  the  cage  has  passed  down  the  shaft, 


SAFETY  APPLIANCES 


291 


the  lever  is  returned  to  its  first  position,  putting  the  piece  C,  in  place,  ready  for 
the  next  landing.  Owing  to  the  hinged  construction  at  B,  the  catching  of  the 
cage  by  C  is  automatic,  as  the  piece  simply  lifts  when  the  cage  comes  into  con- 
tact with  it,  and  falls  into  place  when  the  cage  rises  above  it.  The  total  friction 
of  the  apparatus,  most  of  which  occurs  at  the  rubbing  surface  Y,  is  so  small  that 
with  a  load  of  5  tons  resting  on  the  chair,  a  force  of  less  than  45  Ib.  at  the 
handle  will  suffice  to  operate  the  mechanism.  One  of  these  chairs  is  placed  on 
each  side  of  the  shaft,  and  by  means  of  a  connecting  rod  both  are  operated  by 
the  same  lever.  As  used  at  Flat  River,  the  beam  upon  which  the  chair  is 
mounted,  is  cushioned  by  a  spiral  spring  placed  beneath. 

Chairs  on  the  Cage. — In  the  effort  to  do  away  with  the  chairs  in  a  shaft, 
many  devices  have  been  tried.     An  apparatus  similar  to  the  one  described  here 


FIG.    207. — CAGE   CHAIRS. 

can  be  made  in  any  mine  shop  and  will  give  satisfaction.  Referring  to  Fig. 
207,  the  levers  a  a  carrying  the  chairs  are  four  in  number  and  are  set  at  each 
corner  of  the  cage  floor  b  b,  just  within  the  side  rods.  As  shown,  they  are 
connected  by  the  rods  c  c  to  rocker  arm  r,  and  are  held  clear  of  the  shaft  when 
the  cage  is  in  motion  by  the  powerful  spring  s.  The  shaft  d  and  bars  e  e  ex- 
tend across  the  cage  and  the  arrangement  is  duplicated  on  the  other  side.  Thus 
a  movement  of  any  lever  actuates  all.  The  chairs  rest  on  blocks  with  sheet- 
iron  caps  placed  at  each  corner  of  the  shaft  compartment.  The  height  of 
these  blocks  is,  of  course,  such  as  will  insure  alignment  of  the  cage  rails  with 
those  on  the  station.  The  mechanism  can  be  operated  from  the  cage  or 
station  floor. 

Landing  Chair  for  Cage  (By  C.  L.  Severy).— The  cage  chair  shown  in 
Fig.  208  was  designed  at  the  Poderosa  mine,  Collahuasi,  Chile,  to  overcome  the 
difficulties  in  the  use  of  the  ordinary  kind  where  the  timbers  of  the  shaft  were 
continually  shifting  due  to  bad  ground.  Since  this  chair  was  put  into  use  no 
trouble  whatever  has  been  experienced,  for  as  long  as  the  cage  will  pass  through 
the  shaft  the  chairs  are  ready  for  use.  The  advantages  of  this  style  of  chair  are 


292 


HANDBOOK  OF  MINING  DETAILS 


many.  Only  one  chair  is  needed  for  each  cage.  They  are  quicker  to  operate 
in  changing  levels  and  in  case  of  accident  with  men  aboard  they  can  be  seated 
on  any  set  in  the  shaft.  This  feature  is  convenient  in  shaft  repair  work.  They 
add  little  more  weight  to  the  cage  and  are  so  simply  and  easily  operated  that 
boys  of  12  years  who  can  hardly  reach  the  handle  operate  them  here.  The 
chairs  can  be  easily  attached  to  any  cage. 

The  construction  of  the  chair  is  simple,  being  a  system  of  levers  to  throw  out 
four  iron  rods,  one  at  each  corner  of  the  cage,  for  it  to  rest  upon,  these  levers 
being  operated  by  another  upright  lever  extending  above  the  top  of  the  car,  on 


ip  to  hold  Handle 
in  Position 


Bottom  View  Front  View 

FIG.    208. — CAGE   FITTED    WITH  LANDING   CHAIRS. 

the  cage.  The  four  rods  for  seating  the  cage  are  of  i  i/4-in.  square  iron  and 
upset  at  the  proper  point  for  a  pin  run  through  holes  in  channel  irons  as  guides, 
the  channel  irons  being  riveted  to  the  bottom  of  the  cage.  The  center  pivot  for 
the  levers  is  riveted  to  the  middle  of  the  T-iron  on  the  under  side  of  the  cage. 
The  long  arm  of  the  operating  lever  is  made  of  iX5/8-in.  steel.  The  handle 
is  also  made  of  steel  so  as  to  insure  strength  and  to  give  it  the  necessary  spring 
to  hold  it  behind  a  pin  at  the  side  of  the  cage  to  keep  the  chair  from  jarring  open 
while  the  cage  is  in  motion. 


SAFETY  APPLIANCES 


293 


A  Safety  Gate  for  Cages  (By  R.  B.  Wallace).— In  vertical  shafts  an  open 
cage  is  often  used  for  hoisting  men  in  preference  to  one  inclosed  with  sheet 
metal.  Fig.  209  shows  a  gate  for  an  open  cage  which  gives  a  full  opening  and 
which  can  be  used  where  there  is  not  sufficient  room  for  an  up-  and  down-sliding 
gate.  The  bars  of  the  gate  are  hinged  on  one  side  and  fold  up  to  a  vertical 
position  where  they  are  held  by  a  hook  that  fastens  into  one  of  the  handles  of  the 
gate.  The  top  bar  is  i  in.  square  while  the  other  cross  bars  measure  iX  1/4  in. 
These  are  loosely  riveted  together.  Two  channels  C  made  from  plate  and  bolted 


FIG.    209. — A  FOLDING   SAFETY   GATE. 

or  riveted  to  the  sides  of  the  cage  hold  the  gate  in  position.  Two  handles  H  are 
placed  in  convenient  positions  on  the  cross  strips  for  the  cage  conductor  to 
grasp  when  raising  the  gate. 

A  Safety  Device  for  Cages  at  the  ChapinMine. — Many  accidents  in  mine 
shafts  are  due  to  carelessness  on  the  part  of  the  gate  tenders  in  failing  to  close 
the  bars  to  keep  the  mine  car  in  its  place.  Moreover,  it  is  possible  for  this  bar 
to  be  knocked  out  of  place  by  a  projecting  timber  or  otherwise,  resulting  in  the 
car  rolling  off  the  cage  and  catching  in  the  shaft  timbers.  The  device  shown  in 
Fig.  210  has  been  used  many  years  at  the  Chapin  mine,  Iron  Mountain,  Mich., 
where  it  has  proved  a  success  in  preventing  accidents  of  this  kind.  It  consists 
of  a  drop  track  directly  under  the  wheels.  This  track  can  be  thrown  into  posi- 
tion only  by  setting  the  cage  on  both  chairs.  The  instant  the  cage  is  lifted  from 


294 


HANDBOOK  OF  MINING  DETAILS 


the  chairs  the  track  drops  down  2  1/2  in.  so  that  it  is  impossible  for  a  car  to  roll 
off,  even  should  the  bars  not  be  in  place.  The  iron  bar  a  used  to  support  the 
drop  track  is  2  X  4  in.  and  as  long  as  the  cage.  The  drop  section  of  the  rail  is 


FIG.    2IO. — SAFETY    DEVICE    FOR   CAGES. 


10  in.  long.  The  bar  is  supported  in  a  slot  b  that  allows  2  1/2  in.  play  and  is 
secured  by  an  angle-iron  lug  c  so  that  it  cannot  slip  endwise.  It  is  operated 
entirely  by  the  contact  of  the  cage  with  the  chairs  at  the  desired  landing. 

Shaft  Gates. — The  type  of  shaft  gates  shown  in  Fig.  211  gives  satisfactory 


FIG.  211. — OPERATION  OF  SHAFT  GATES. 


results  and  is  of  simple  and  inexpensive  design.  The  gate  a  is  built  with  iron 
guides  as  shown  in  the  plan,  which  allow  it  to  travel  up  and  down  the  guide 
posts.  When  the  cage  comes  out  of  the  shaft  mouth,  it  strikes  the  iron  b  on  the 


SAFETY  APPLIANCES 


295 


back  of  the  gate,  lifting  it  out  of  the  way  until  the  cage  is  again  dropped.  In 
case  of  overwinding,  the  gate  is  diverted  by  the  guide  at  the  point  c,  and  swings 
clear  of  the  cage  into  the  position  marked  d  on  the  drawing.  This  same 
arrangement  may  be  used  on  both  sides  of  the  shaft  so  that  as  the  loaded  car 
is  run  off  the  empty  may  be  run  directly  upon  the  cage  and  lowered,  thus 
saving  considerable  time.  The  advantage  of  these  gates  raised  by  the  cage  lies 
in  the  fact  that  the  necessity  for  a  top  man  to  watch  the  shaft  is  eliminated,  and 
an  additional  guard  is  afforded  against  danger  from  persons  falling  down  the 
shaft,  as  it  is  difficult  to  lift  the  gates  without  raising  the  cage.  Where  there 
is  little  danger  of  overwinding,  the  guides  for  the  gates  may  be  made  of  channel 
irons  or  straight  posts  without  the  notching  shown  at  d.  The  gate  itself  may 
be  made  of  any  desired  dimensions  or  construction. 

Anaconda  Gates  (By  F.  L.  Fisher). — In  several  of  the  Anaconda  company's 
mines  at  Butte,  where  ore  is  hoisted  in  skips,  it  has  been  found  necessary  to 


FIG.    212. — STATION   GATES    IN   A   BUTTE    MINE. 

protect  the  openings  from  the  shaft  to  the  stations  from  occasional  falls  of  small 
quantities  of  ore  that  are  inevitably  spilled  in  loading.  To  insure  against  acci- 
dents from  this  source,  swinging  gates  have  been  devised  and  are  installed  at 
the  stations.  The  main  gates  A,  in  Fig.  212,  are  made  of  two  wide  vertical 
strips  of  i/8-in.  iron  sheeting  C,  and  a  central  screen  of  i-in.  mesh,  No.  8  iron 
wire,  all  bordered  by  a  2-in.  angle  iron  D,  and  crossed  horizontally  by  two  strips 
of  3/8-in.  iron  E.  The  doors  are  hung  on  hinges  F,  and  locked  with  lift-latch 
G,  which  can  be  operated  from  either  side.  They  are  attached  to  the  outward 
faces  of  the  first  station  sets  H,  which  are  separated  from  the  shaft  timbers  by 
a  space  of  2  in.  Above  and  back  of  these  doors  is  a  second  set  of  doors  7, 
hung  from  the  center  of  the  cap  at  the  top  of  the  shaft-station  sets  by  hinges  J, 
so  that  the  doors  can  be  swung  in  and  out  of  the  shaft,  to  facilitate  the  unloading 


296 


HANDBOOK  OF  MINING  DETAILS 


of  long  timbers  from  the  cages;  the  doors  being  simply  swung  up  and  away  from 
the  shaft  as  the  timbers  are  dragged  through.  The  bottoms  of  the  upper 
doors  are  12  in.  above  the  tops  of  the  lower,  and  22  in.  back  toward  the  shaft. 
They  are  made  of  i/8-in.  iron  sheeting,  strengthened  by  two  vertical  strips  of 
3/8-in.  iron  K,  and  of  their  own  weight  they  tend  to  deflect  any  falling  pieces 
of  ore  to  the  turnsheet  below,  where  the  lower  gates  prevent  them  from  bounding 
into  the  station.  The  opening  between  the  gates,  and  the  wire  screens  on  the 
lower  gates  are  for  the  purpose  of  admitting  light  to  the  shaft. 

Guards  at  Shaft  Stations.— At  the  stations  of  the  inclined  shafts  in  the 
Michigan  copper  district  many  different  kinds  of  guards  have  been  tried.  At 
some  shafts  a  wire  rope  or  a  light  chain  is  used  having  a  hook  at  its  end  that 
fastens  to  a  ring  carried  by  a  post  at  the  hanging-wall  side  of  the  shaft.  It  is 


FIG.    213. A    SIMPLE    IRON    SHAFT   GUARD. 

an  unhandy  device  as  the  men  have  to  go  clear  over  to  the  foot  wall,  stoop  down 
and  pick  up  the  chain  each  time  to  put  it  across  the  shaft  opening.  At  other 
inclines  the  shaft  bar  that  is  in  common  use  at  vertical  shafts  has  been  copied. 
Owing  to  the  length  that  this  guard  arm  must  have  at  the  inclines,  and  its  weight, 
a  counterweight  is  sometimes  arranged  to  make  the  lifting  of  the  arm  easier.  A 
nail  driven  into  the  post  that  carries  the  stop  on  which  the  guard  arm  rests  holds 
the  arm  out  of  the  way,  when  it  is  raised  and  a  car  is  being  dumped. 

A  guard  arm  is  handier  than  a  chain,  but  the  best  form  of  bar  for  the  inclined 
shaft  stations  consists  of  a  3/4-in.  iron  rod  that  is  bent  at  each  end  so  as  to  have 
arms  i4-in.  long  with  eyes  in  them  that  hook  into  an  eye-bolt  that  is  fastened 
into  the  two  posts  of  the  fence  that  is  built  around  the  shaft  at  the  station.  These 
posts  are  about  3  1/2  ft.  high  and  the  eye-bolts  are  placed  about  7  in.  from  the 
top,  and  extend  out  from  the  posts  about  3  1/2  in.  Therefore  when  the  guard  is 
turned  up  so  that  a  car  can  be  dumped  into  the  skip  it  rests  against  the  top  of  the 


SAFETY  APPLIANCES 


297 


posts  and  will  not  jar  down  easily.  As  soon  as  the  car  is  dumped  the  bar  is 
given  a  push  so  that  it  swings  down  to  prevent  any  car  from  being  pushed  into 
the  shaft.  This  guard  is  illustrated  in  Fig.  213. 


NOTES  ON  MINE  TRACK  AND  SWITCHES 

Mine  Track  (By  Alvin  R.  Kenner). — A  poorly  laid  mine  track  is  the  cause 
of  much  trouble  and  the  additional  time  required  to  lay  it  properly  will  be  saved 
many  times  over  by  the  avoidance  of  derailed  and  overturned  cars.  When 
laying  short  lengths  of  rail  for  a  temporary  track  in  the  face  of  a  drift  tunnel  or 
crosscut  there  is  usually  a  tendency  upon  the  part  of  the  tracklayer  to  put  the 
ties  in  carelessly  with  the  intention  of  fixing  them  properly  when  the  permanent 
rails  are  placed.  When  this  time  comes  it  is  too  much  work  to  dig  out  each  tie 
and  place  it  properly.  If  the  ties  are  placed  permanently  the  first  time  a  much 
better  track  will  result,  especially  if  short  pieces  of  rail  are  dispensed  with  and 
full  length  rails  used  instead,  in  the  manner  here  described. 


FIG.    214. — EXTENDING  TRACK   WITHOUT   USING   SHORT   RAILS. 

Lay  the  ties  permanently  as  near  the  face  as  advisable  and  place  two  full 
length  T-rails  as  shown  by  the  full  lines  in  Fig.  214,  on  the  outside  of  the  last 
set  of  permanent  rails.  Drive  a  track  spike  at  both  ends  of  the  lap  of  each  pair 
of  overlapping  rails  to  hold  the  new  rail  against  the  old,  and  the  track  is  ready 
for  the  car.  As  the  heading  advances  slide  the  rails  forward.  When  the  ends 
are  reached,  turn  over  and  spike  them  in  place.  After  the  face  is  advanced  a 
few  feet  two  new  rails  are  placed  as  before. 

A  decided  advantage  of  this  method  is  due  to  the  stability  of  the  rails  near 
the  face  due  to  the  fact  that  they  are  fastened  to  the  track  behind.  This  permits 
advancing  the  ends  much  nearer  to  the  face  than  when  short  rails  are  used,  and 
the  car  can  always  be  brought  into  close  proximity  to  the  muck  pile.  Instead 
of  track  spikes  being  used  to  hold  the  new  rails  in  place,  a  block  may  be  nailed 
on  a  tie  and  a  wedge  driven  between  the  block  and  the  rail.  The  block  being 
on  the  outside  of  the  rail  need  not  be  removed.  In  spiking  the  new  rails  to  the 
ties,  spikes  should  only  be  driven  on  the  outside  and  when  the  rails  are  turned 
over,  these  will  be  found  to  be  correctly  placed  for  spiking  down  one  side  of 
the  base  of  the  rail  and  need  only  to  be  driven  down. 


298 


HANDBOOK  OF  MINING  DETAILS 


This  method  is  even  more  useful  in  the  sinking  of  an  inclined  shaft  or  in 
advancing  the  waste-dump  track  than  in  driving  headings.  In  sinking  an 
inclined  shaft  with  a  skip,  a  source  of  annoyance  is  the  false  track  necessary  to 
bridge  the  distance  from  the  last  set  of  timbers  to  the  bottom  of  the  shaft.  A 
long  set  of  rails  will  work  better  than  a  false  track  and  has  the  added  advantage 
of  being  readily  extended  below  the  water  level  and  remaining  in  a  fixed  position. 
In  unwatering  and  retimbering  an  old  inclined  shaft  this  was  of  great  assistance 
making  it  possible  to  lower  the  water  sufficiently  to  put  in  a  new  set  of  timbers, 
as  readily  as  though  the  track  were  already  in  place.  In  hoisting  water  from  a 
sump  where  only  two  shifts  could  be  used  in  sinking,  the  engineer  on  the  third 
shift  was  annoyed  by  the  skip  jumping  the  false  track  and  tearing  out  timbers. 
By  adopting  this  method  the  trouble  was  eliminated. 

In  advancing  a  dump  track,  lack  of  stability  is  often  the  cause  of  the  car 
going  over  the  dump.  To  avoid  this  the  new  rails  are  not  only  firmly  fastened 
to  the  old  track  but  the  rear  ends  of  the  new  rails  are  so  placed  that  the  outer 
ends  cannot  give  downward  except  by  bending.  .  A  support  at  the  outer  end  of 
a  set  of  rails  placed  as  suggested  will  give  dumping  room  for  a  considerable 
period  of  time,  as  the  new  rails  are  easily  pushed  forward  any  distance  desired. 

A  similar  system  which  is  much  used  is  indicated  by  the  dotted  lines  in  the 
illustration.  This  method  of  placing  the  rails,  however,  has  a  drawback  in  that 
muck  accumulates  rapidly  in  the  groove  of  the  new  rail  and  causes  annoyance. 

A  New  Track  Spike. — A  new  track  spike,  the  invention  of  W.  H.  Floessell, 

Hole  for  Tin 


I 

1  L_ 

/ 

Piu  to  keep  Wedge  in  Place. 

I 

r 

Ti 

> 

\Sp\ke  S\ 

L 

y     :x^pikH 

Plan. 


A«  Engineering  g 
Mining  Journal 


FIG.    215. — METHOD    OF   FASTENING   A   GUARD    RAIL. 

of  Sydney,  N.  S.  W.,  has  been  tested  by  W.  H.  Warren,  professor  of  engineering 
at  Sydney  University  and  proved  to  have  1.29  times  the  holding  power  of  a  black- 
iron  spike  of  square  section  and  1.30  times  that  of  one  of  circular  section.  The 
spike  is  made  by  twisting  a  bar  of  square,  hexagonal  or  octagonal  cross-section, 
so  as  to  form  a  helix  of  large  pitch,  and  a  square  head  is  forged  at  the  top.  The 


SAFETY  APPLIANCES 


299 


original  bar  can  be  of  fluted  or  plain  section.  The  spike  is  driven  into  a  hole 
bored  to  a  depth  of  4  in.  in  a  railway  sleeper;  the  spike  revolves  as  it  is  driven 
into  the  hole. 

Short  Guard  Rail  and  Fastening  (By  G.  M.  Shoemaker).— A  satisfactory 
guard  rail  and  method  of  fastening  is  shown  in  Fig.  215.  A  shorter  piece  of  rail 
may  be  used  in  making  it  than  with  the  older  method.  The  purpose  of  a  guard 
rail  is  to  guide  the  flange  of  the  wheel  away  from  the  point  of  frog  and  6  in.  of 
rail  should  be  sufficient  to  do  this,  3  in.  on  either  side  of  the  point  of  frog. 
With  the  old  method  it  is  necessary  to  use  a  much  longer  piece  to  get  sufficient 
spiking  surface  to  make  the  rail  fast.  In  the  old  method,  unless  notches  are  cut 
in  the  bases,  it  is  necessary  to  drive  the  spikes  between  the  outer  rail  and  the 
guard  to  prevent  the  base  of  each  from  meeting.  By  this  method  the  ball  of  each 
rail  is  brought  closer  together  thereby  making  the  liability  of  derailment  less, 
especially  so  in  the  case  of  a  bent  axle  or  a  wheel  which  has  become  wobbly 
from  wear  on  bore  or  axle. 

Mining  Track  Frog. — The  cheap,  simple  but  effective  device  shown  in 
Fig.  216  is  used  in  some  of  the  Utah  mines  for  guiding  the  wheels  of  mine  cars 
to  the  rails  when  passing  from  a  smooth  floor  or  from  a  turntable.  It  is  com- 
posed of  a  piece  of  2-in.  plank,  15  in.  wide  (if  used  with  i8-in.  track) 


FIG.    2 1 6. — TRACK  AND    FROG. 

and  2  1/2  ft.  long.  One  end  is  cut  into  a  rojmding  point  and  the  edge 
of  the  plank  is  protected  by  a  piece  of  strap  iron,  2  in.  wide,  nailed  on.  The 
device  is  then  spiked  down  between  the  ends  of  the  rails,  with  the  point  toward 
the  turning  place,  leaving  enough  space  between  the  edges  and  the  inner  sides 
of  the  rails  for  the  flanges  of  the  wheels  to  pass.  Unlike  most  other  devices  for 
this  purpose,  this  contrivance  does  not  get  battered  out  of  shape,  does  not  require 
a  blacksmith  to  make  it,  and  never  fails  in  its  duty. 

Mine  Track  Switches. — At  many  mines  it  is  the  practice  to  order  standard 
switches  direct  from  supply  companies,  while  at  others  the  switches  are  made 
at  the  mine,  usually  by  the  blacksmith,  who  makes  them  according  to  his  own 
ideas,  guided  by  the  data  supplied  by  the  foreman  of  the  track-laying  crew. 
Standard  switches  are  expensive  when  bought  from  supply  houses.  Made-at-the- 


3oo 


HANDBOOK  OF  MINING  DETAILS 


mine  switches  are  comparatively  cheap,  but  unless  well  made  they  cause  much 
trouble  from  cars  being  derailed.  At  the  mines  of  the  Tonopah  Mining  Co., 
the  engineering  corps  designed  the  switches  illustrated  in  Fig.  217.  These  are 
made  at  the  company's  shops  according  to  standard  specifications  and  are  suit- 
able for  tracks  where  the  tramming  is  done  by  hand.  The  car  is  made  to 
take  the  turn  by  shifting  the  rear  end  in  the  opposite  direction.  The  switches 
are  so  placed  that  only  the  empty  cars  need  be  so  shifted;  the  loaded  cars,  run- 
ning in  the  opposite  direction,  take  the  straight-away  track. 


FIG.    217.  —  ONE-   AND   TWO-WAY   MINE    SWITCHES. 

Calculating  a  Crossover  Switch.  —  The  following  formulas  for  calculating 
the  lengths  and  distances  required  to  lay  a  crossover  switch  between  two  parallel 
tracks  in  a  mine  were  published  in  Coal  Age.  The  data  usually  given  are:  The 
frog  number,  «;  the  gage  of  the  track,  g\  and  d,  the  track  centers.  The  data 
required  are  found  by  the  following  formulas:  The  chord  of  lead  rail,  c=  2  ng; 

the  radius  of  lead  rail,  R=nc;  the  frog  angle,  sin.  1/20=  —  ;  the  length  of  lead 


rail,  L=~  —  R-,  the  length  of  the  follower,  /=  —  ^—  L;  the  length  of  straight 

I  oOTT  £\. 


track,  r 


;  the  lead  of  switch,  x=R  sin.  a-,  the  frog  distance  apart, 


sin.  a 

y=r  cos.  a—  g  sin.  a',  and  the  distance  between  switches,  D=  2X+  y.     The  letters 
in  the  formula  refer  to  the  dimensions  specified  in  Fig.  218. 


SAFETY  APPLIANCES 


301 


Gravity  Tram  Switch  (By  B.  A.  Statz).— While  operating  a  small  milling 
plant  near  Kelly,  N.  M.,  I  had  trouble  with  a  surf-ace  tram  connecting  the  mine 
and  mill  and  having  a  total  length  of  2300  ft.  The  tram  line  was  single  track, 
with  a  30-in.  gage,  having  a  switch  or  turnout  in  the  center;  the  brake  was  of  a 
drum  type,  so  arranged  that  each  car  had  to  pass,  coming  and  going,  on  the  same 
side  of  the  switch.  The  grade  of  the  tram  line  ranged  from  15  to  40°.  The 


* 


s£ 

$ 


.Point 


r*-—  .  ~- 

k  *-/ 

U-.  / 

^J.  x 

H 

^J"S 

./ 

*L* 

1 

FIG.    2l8. — CALCULATING  A   CROSSOVER   SWITCH. 

cars  used  held  two  tons  of  material  and  had  straight  bodies.  When  the  cars 
were  running  at  fairly  good  speed  the  front  wheels  of  the  cars  would  be  i  in. 
above  track  when  on  the  steepest  grade,  hence  when  the  cars  came  to  the  lesser 
grade  the  front  wheels  nearly  always  missed  the  track,  causing  delay.  To 
overcome  this  I  put  in  the  switch,  shown  in  Fig.  219;  the  switch  was  cast  in  a 
local  foundry.  This  arrangement  worked  admirably  in  conjunction  with  cars 
designed  so  that  the  top  line  was  level  when  the  car  was  on  the  steepest  grade. 


Bottom 


FIG.    219. — SWITCH  FOR   GRAVITY   TRAM. 


A  switch  such  as  is  shown  in  the  accompanying  drawing  was  put  in  at  both 
ends  of  the  turnout.  The  tongues  of  these  switches  were  made  of  wrought  iron 
and  coupled  together.  These  slid  over  a  cast-iron  bed  plate.  The  switches 
were  set  opposite  from  one  another,  of  course,  so  that  the  car  would  pass  on  the 
switch.  Consequently,  the  car  coming  up  would  throw  over  the  tongues  of  the 
switch  at  the  head  of  the  turnout,  while  the  car  going  down  would  throw  over 
the  tongues  of  the  switch  at  the  bottom  end  of  the  turnout.  So,  when  the  car  at 


302 


HANDBOOK  OF  MINING  DETAILS 


the  top  was  loaded  and  the  car  at  the  bottom  dumped,  and  they  began  their 
journeying  again,  the  switches  were  set  so  that  each  car  traveled  along  the  same 
side  of  the  turnout  that  it  had  taken  before. 

A  Double  Gage  Turnout. — The  turnout  shown  in  Fig.  220  is  used,  states 
Frederick  MacCoy  (Eng.  News,  Jan.  25,  1912),  wherever  36-in  and 4  ft.  8^-in. 
tracks  are  employed  together  at  the  Esperanza  mine  in  the  El  Oro  district, 
Mexico.  A  motor  car  runs  on  the  narrow-gage  tracks,  drawing  either  narrow- 
er standard-gage  cars.  One  lever  is  used  to  operate  both  switches.  Frogs  A 
and  B  are  standard  while  C  is  a  crossing  frog. 

An  Automatic  Switch. — The  accompanying  illustration,  Fig.  221,  indicates 
the  design  of  a  switch  operated  by  gravity  instead  of  a  spring.  It  can  be 


FIG.    22O. — DOUBLE-GAGE   TURNOUT   USED    ON    MINE    TRACKS. 

easily  used  on  trestles  where  there  is  space  beneath  the  tracks.  It  consists 
simply  of  the  ordinary  two  short  rails  fastened  together  as  in  the  case  of  a  spring 
switch.  Beneath  the  connecting  bar  is  a  small  lug  which  is  engaged  by  an  L- 
shaped  lever.  One  arm  of  the  lever  is  2  ft.  long,  and  the  other  i  ft.  At  the  angle 
point  it  is  fastened  to  a  post  or  beam.  The  short  arm  has  a  wide  face  which  en- 
gages the  lug  on  the  bar  above,  and  by  means  of  a  small  weight  on  the  end  of 
the  lever  it  throws  the  switch.  It  works  satisfactorily,  and  has  been  in  use  by 
the  Cleveland-Cliffs  Iron  Co.  for  a  number  of  years.  It  is  arranged  so  that  it  is 
opened  by  the  loaded  cars  and  then  closes,  thus  throwing  the  empty  cars  on  an- 
other track  upon  their  return. 


SAFETY  APPLIANCES 


303 


FIG.    221. GRAVITY    SWITCH   FOR   ORE   CARS. 


FIG.    222. — THE    PETERSEX   SWITCH. 


HANDBOOK  OF  MINING  DETAILS 


A  Convenient  Switch-throwing  Device. — The  switch-throwing  device 
shown  in  Fig.  222  is  in  use  at  the  Homestake  mine,  and  is  made  at  Newport 
News,  Va.,  by  Peter  H.  Petersen,  a  former  employee  of  the  Homestake  company. 
The  function  of  the  apparatus  is  to  permit  the  switch  being  set  in  either  position: 
When  trailing  a  closed  switch  no  adjustment  is  necessary,  the  action  being  auto- 
matic; and  when  facing  it,  the  required  adjustment  can  be  made  by  the  engineer 
from  the  train.  The  device  consists  of  a  triangular  lever  box  composed  of  two 
plates  spaced  by  roller-shaped  fillers  on  the  bolts,  and  pivoted  at  D.  The 
switch  rails  are  connected  to  this  lever  box  through  a  bell  crank  and  bar  E, 
which  is  pivoted  at  the  bolt  M .  The  gravity  lever  B  with  weight  P  is  pivoted  be- 
tween the  plates  at  D.  When  B  is  in  the  position  shown,  it  rests  on  the  bolt  C 
and  holds  the  switch  points  against  the  right-hand  rail,  thus  keeping  the  left- 
hand  track  open.  When  B  is  thrown  over  center,  it  rests  on  the  bolt  A ,  raising 
E  and  holding  the  points  in  the  opposite  position. 


if* 


Track 


Track 


Track 


Track 


(10  diam.  1'wide) 
Axis 

FIG.    223. — TURNTABLE   USED    IN  HIGHLAND    BOY   MINE. 

When  trailing  a  closed  switch,  no  matter  for  which  track  it  is  closed,  the 
switch  points  will  open  to  let  the  cars  pass  through  and  adjust  themselves  again 
to  their  former  position  after  the  last  car  has  passed  over  them.  The  engineer 
or  motorman  can  throw  the  lever  to  set  the  switch  for  either  track  he  desires 
while  his  locomotive  is  passing  over  the  switch  points.  When  facing  a  switch, 
should  it  be  placed  wrong,  the  engineer  drives  to  the  throw,  adjusts  it  to  suit, 
and  then  moves  off  the  switch  points,  whereupon  the  weight  sets  the  switch  to 


SAFETY  APPLIANCES 


305 


its  new  position.  Or  a  rope  may  be  attached  to  B,  run  through  a  pulley  directly 
over  the  pivot  D  and  extended  to  any  point  along  the  track,  permitting  the  engi- 
neer to  set  his  switch  as  he  approaches  it.  Thus  no  switchman  or  extra 
trainman  is  necessary. 

Turntable  for  Mine  Cars. — A  turntable  of  simple  construction  and  requir- 
ing no  bed  other  than  an  ordinary  tie  is  shown  in  Fig.  223.  In  place  of  switches 
or  iron  plates  such  small  turntables  are  used  at  tunnel  crossings,  in  the  Highland 
Boy  mine  of  the  Utah  Consolidated,  Bingham  Canon.  The  turntables  act 
quickly,  are  easy  and  cheap  to  build  and  keep  in  repair,  and  save  space  at  the 
tunnel  junctions.  A  piece  of  i/4-in.  iron  plate  is  riveted  to  two  3/4X  i-in.  iron 


Drilled  «d   »£S        2  Rails  of 
CQunt«Huak          2«  by  iH-in.  Steel 

FIG    224. — TURNTABLE   USED    IN   SOME   MICHIGAN   COPPER   MINES. 

strips  placed  with  the  larger  dimension  vertical  and  spaced  the  same  as  the 
tracks,  a  continuation  of  which  they  form.  A  hole  for  a  3/4-in.  spike  is  punched 
in  the  center  of  the  i/4-in  plate  and  on  its  under  side  about  the  center  point  a 
ring  of  i/4X  i-in.  iron  10  in.  in  diameter,  is  riveted.  This  completes  the  turn- 
table. A  tie  slightly  over  10  in.  wide  is  laid  at  the  point  about  which  the  turn- 
table must  pivot  and  to  this  it  is  spiked.  The  spike  acts  as  the  pivot  and  the 
ring  on  the  underside  of  the  i/4-in.  plate  serves  as  a  bearing  on  the  surface  of  the 
tie.  A  plentiful  supply  of  grease  is  provided  at  this  point  to  keep  the  table  turning 
easily.  There  is  practically  no  opportunity  for  dirt  to  get  on  this  bearing  sur- 
face, so  little  attention  is  required  for  the  device. 

A  Ball-bearing  Turntable. — Turntables  are  generally  used  at  the  shaft 
stations  in  the  inclined  shafts  of  the  Lake  Superior  copper  country,  as  the  tram 

20 


306  HANDBOOK  OF  MINING  DETAILS 

cars  generally  hold  from  i  3/4  to  2  1/2  tons.  At  the  Tamarack,  however,  where 
the  shafts  are  vertical  and  the  cars  hold  21/2  tons  as  loaded,  turnplates  are 
used.  These  are  somewhat  thicker  and  hence  more  rigid  than  turnsheets, 
the  usual  substitute  for  turntables  in  other  districts.  The  turntables  are  not 
especially  rapid  in  operation  as,  owing  to  the  weight  of  the  loads,  speed  is  not  so 
important  as  in  Western  mines  where  ton-cars  are  used.  The  turntables  are 
put  in  the  main  tracks  on  the  hanging- wall  side  of  the  shaft  and  are  used  so  as 
to  get  the  cars  on  the  short  tracks  that  lead  right  up  to  the  edge  of  the  plat. 
Some  of  these  turntables  are  made  with  ball  bearings,  while  others  have  two 
flat  bearing  rings.  The  turntables  with  the  balls  are  stiff  at  first,  but  after  the 
balls  have  worn  smooth  they  are  superior  to  those  with  bearing  rings.  If  any- 
thing, the  top  part  of  the  turntable  could  be  cast  a  little  heavier  as  occasionally 
an  arm  breaks.  The  gage  shown  is  3  ft.  4  in.  which  is  the  standard  of  many 
mines  in  the  copper  country.  Fig.  224  shows  the  turntables  used  in  the  Wolver- 
ine and  Mohawk  mines;  the  Calumet  &  Hecla  company  uses  a  similar  table  on 
tracks  of  4-ft  gage. 


XI 

PUMPING  AND  DRAINING 

Operation  of  Pumps — Air  Lifts  and  Eductors — Mine  Drainage 

OPERATION  OF  PUMPS 

A  Useful  Pump  Formula  (By  A.  Livingstone  Oke). — Some  years  ago, 
while  in  charge  of  the  work  of  unwatering  a  mine  in  Portugal,  I  noticed  the 
following  simple  relation  between  the  tons  of  water  delivered  per  hour  by  the 
pump  and  the  diameter  in  inches  of  the  pump  plunger,  or  piston:  Tons  per  hour 
equal  the  plunger  displacement  in  cubic  feet  per  hour  times  the  weight  of  a 
cubic  foot  of  water  divided  by  the  number  of  pounds  in  a  ton. 

r  =  <PX22XiooX6oX62.s 

4X7X144X2000 

or  only  2.3  per  cent,  more  short  tons  than  the  square  of  the  plunger  diameter  in 
inches.  For  the  long  ton  the  value  is  d2X 0.924,  or  7.6%  less  than  the  square 
of  the  plunger  diameter  in  inches. 

These  factors  are  based  on  the  assumption  that  the  piston  speed  is  100  ft. 
per  minute,  which  is  that  usually  adopted  in  ordinary  reciprocating  steam  and 
other  pumps.  In  any  case  the  formula  is  easily  applied  by  multiplying  the  speed 
and  dividing  by  100.  It  will  be  seen  then  that  the  square  of  the  diameter  of  a 
pump  plunger  expressed  in  inches  is  nearly  the  same  as  the  short  tons  it  will 
deliver  in  an  hour,  neglecting  slip.  In  dealing  with  long  tons,  this  amount 
should  be  reduced  by  one-tenth,  thus  an  8-in.  pump  will  deliver  (8X8)  — 6.4= 
57.6  long  tons,  which,  in  most  cases,  will  be  rather  over,  than  under,  the 
actual  amount  on  account  of  slip  in  the  valves.  In  short  tons  it  is  quite  close 
enough  to  say  that  it  is  simply  the  square. 

This  formula  is  applicable  to  pipes  when  the  rate  of  flow  per  minute  is  known. 
Thus  a  4-in.  pipe,  through  which  the  water  is  flowing  at  400  ft.  per  minute  is 
delivering  4X4X4  =  64  tons  of  water  per  hour.  In  approximations  where  the 
spouting  velocity  and  nozzle  diameter  are  known,  the  values  obtained  will  be, 
of  course,  a  little  high,  but  the  formula  affords  a  means  whereby  a  rapid  cal- 
culation gives  a  quantitative  approximation.  I  have  often  found  this  formula 
surprisingly  useful  when  examining  mines  where  numerous  small  pumps  are 
in  use,  and  also  in  rapidly  approximating  the  capacity  of  pipe  lines. 

Unwatering  Flooded  Mines  (By  D.  Lament). — It  often  occurs  in  opening 
an  old  mine  that  a  considerable  quantity  of  water  has  to  be  removed.  I  pro- 
pose to  give  a  few  details  and  hints,  gleaned  from  actual  experience  as  to  the 

307 


308  HANDBOOK  OF  MINING  DETAILS 

plant  required  for  this  work,  its  installation  and  working.  I  do  not  propose  to 
deal  with  elaborate  and  costly  installations,  such  as  have  been  used  in  some 
cases,  but  confine  myself  to  the  style  of  plant  in  more  common  use,  and  which, 
in  nine  cases  out  of  ten,  would  be  used  in  a  medium  undertaking  by  the  average 
engineer  with  an  eye  to  economy  in  first  cost. 

Before  definitely  settling  on  the  size  and  capacity  of  the  pumps  required,  the 
size  of  the  shaft  and  available  space  must  be  considered.  It  is  also  necessary 
to  ascertain  the  amount  of  water  the  mine  is  producing,  and  add  a  percentage 
to  allow  for  extra  water  by  seepage  from  the  surface  during  heavy  rains  or  melt- 
ing snow. 

Many  mines  have  an  adit  level  communicating  with  the  shaft  as  low  as  the 
contour  of  the  country  will  permit.  The  amount  of  water  flowing  from  the  adit 
is  generally  a  fair  guide  to  the  amount  of  excess  water  that  the  mine  is  yielding. 
This  may  be  measured  by  an  ordinary  weir. 

In  ordering  a  pump,  a  good  margin  must  be  allowed  on  its  capacity  for  the 
excess  water.  Of  the  different  types  of  sinking  pumps  little  need  be  said,  as  all 
have  their  particular  merits,  and  an  engineer  or  pumpman  will  generally  swear 
by  the  particular  type  of  pump  with  which  he  has  had  most  experience.  I 
consider  it  a  good  policy  to  give  an  experienced  pumpman  his  choice  of  pump. 

Most  sinking  pumps  can  be  driven  with  either  steam  or  air,  or  both  together. 
The  steam  heats  the  air,  and  increases  its  efficiency  considerably.  If  the  dis- 
tance between  the  boilers  and  pump  is  not  too  great,  the  combination  of  air 
and  steam  prevents  freezing  of  the  exhaust,  which  is  often  a  great  trouble  in 
pumps  using  compressed  air  only.  Compressed  air  is  expensive,  as  it  involves 
the  use  of  steam  or  other  power  to  work  the  compressors.  The  losses  in 
efficiency  through  friction  in  pipes,  leaks,  etc.,  are  also  considerable,  and  although 
compressed  air  is  a  boon  in  a  mine,  it  is  not  always  convenient  in  the  initial 
stages  of  unwatering  the  mine.  Steam  power  is  most  favored  to  begin  with,  as 
fuel  for  boilers  is  obtainable  in  most  parts  of  the  world. 

The  boiler  ordered,  should  be  a  little  in  excess  of  the  actual  horsepower 
required,  and  of  a  type  suitable  for  transport  if  the  mine  is  situated  at  a  distance 
from  the  rail  or  waterway.  The  boilers  should  be  placed  as  near  to  the  shaft  as 
space  and  solid  ground  will  allow. 

If  the  mine  has  been  shut  down  for  a  good  many  years,  it  is  possible  that  the 
shaft  timbers  have  rotted,  or  fallen  in,  and  it  is  always  safe  to  begin  by  putting 
in  a  good  collar  set,  well  spread,  and  carrying  two  or  three  sets  down  on  hanging 
bolts.  The  collar  set  should  be  placed  a  little  above  the  ground  level,  and  the 
ground  sloped  outward,  to  prevent  water  from  entering  the  shaft.  A  temporary 
headgear  should  then  be  erected  over  the  shaft  to  carry  the  weight  of  the  pump. 
A  small  steam  winch  should  be  rigged  in  line  with  the  pulley  for  use  in  lowering 
and  raising  men  and  materials. 

A  crosshead  is  useful,  the  light  timber  guides  for  which  should  be  carried 
down  as  the  work  of  unwatering  proceeds.  A  signal  line  should  also  be  fitted 


PUMPING  AND  DRAINING  309 

in  the  shaft,  and  a  code  of  signals  arranged.  If  the  sides  of  the  shaft  are  in  good 
condition  it  may  not  be  necessary  to  carry  down  the  timber  sets,  and,  in  that  case, 
the  only  timber  required  would  be  the  chain-block  timbers,  and  bearers  for  the 
pump  hangers,  and  cross  timbers  to  carry  the  guides  for  the  crosshead.  These 
should  be  wedged  into  hitches  cut  in  the  wall.  Cross  timbers  should  also  be 
placed  every  50  ft.  or  so,  to  carry  the  weight  of  the  steam  and  water  pipes.  The 
pipes  are  supported  by  clamps.  It  is  a  good  plan  to  arrange  platforms  and 
ladders  in  the  pumping  compartment  for  executing  repairs,  and  to  serve  as  an 
exit  for  the  men,  in  the  event  of  any  accident. 

A  hand  crab-winch  should  be  well  anchored  at  the  surface.  The  pump 
should  be  hung  on  this  with  a  flexible  wire  rope  passing  over  the  pulley,  and 
lowered  through  the  hoist  compartment.  When  the  pump  has  been  lowered 
into  position  and  hung  with  a  set  of  chain  blocks  in  the  pumping  compartment, 
the  rope  should  be  passed  over  the  other  pulley  and  down  the  pump  compart- 
ment and  secured  to  the  hanger  chain  by  a  strong  shackle.  In  this  way  the 
pump  is  always  in  hand,  and,  in  the  event  of  water  rising  in  the  shaft,  it  is 
generally  possible  to  lift  the  pump  out  of  the  water. 

i  f  Sometimes,  even  in  the  case  of  steam  pumps,  a  pump  can  be  made  to  work 
under  water  and  clear  itself.  I  recall  a  case  in  point  where  a  steam  pump 
was  covered  with  6  ft.  of  water.  When  steam  was  turned  on  it  started  easily, 
and  lowered  the  water  to  the  previous  level.  This  was  the  Tangye  Cameron 
pump  with  a  capacity  of  15,000  gallons  per  hour  working  against  a  head  of 
400  ft.,  the  exhaust  being  led  to  surface.  The  exhaust  is  sometimes  carried 
into  the  water.  This  arrangement  has  a  tendency  to  heat  the  water  and  any 
escaping  steam  makes  it  uncomfortable  for  the  men.  Suction  condensers  take 
up  too  much  room  under  the  pump,  and  interfere  with  its  efficient  working. 
I  have  always  found  it  the  best  plan  to  carry  the  exhaust  to  the  surface,  although 
it  entails  a  little  more  work  and  extra  piping. 

Sinking  pumps  are  generally  fitted  with  heavy  hangers  and  hooks  to  take  the 
timbers  top  and  bottom.  With  heavy  heads,  however,  the  vibration  of  the 
pump  is  sometimes  so  great  that  it  is  necessary  to  supply  extra  support  in  the 
shape  of  an  extra  timber  from  the  opposite  wall. 

The  suction  hose  is  generally  a  great  source  of  trouble,  and  it  is  not  always 
convenient  to  use  an  iron-pipe  suction,  as,  in  the  event  of  encountering  debris,  it 
is  essential  that  the  suction  may  be  shifted.  Rubber  suction  hose  as  supplied  by 
the  makers  should  not  be  put  into  a  shaft  without  being  protected  with  tarred 
rope,  or  wound  with  light  chain  of  about  3/i6-in.  link.  If  tarred  rope  is  used, 
the  end  should  be  passed  through  the  bight  at  each  turn.  It  should  not  be 
pulled  too  tight  on  account  of  subsequent  shrinkage  of  the  rope  in  the  water. 
Securing  the  rope  at  each  turn  in  this  way  prevents  it  becoming  unwound  should 
it  be  cut  in  any  part.  A  foot  valve  and  strainer  should  be  used  with  a  strong 
rope  attached,  the  end  being  secured  near  the  pump  platform,  this  greatly 
facilitates  the  handling  of  the  suction  hose. 


310  HANDBOOK  OF  MINING  DETAILS 

It  is  always  best  to  lubricate  the  cylinder  and  slide  valves  from  the  boiler 
room,  or,  at  any  rate,  from  the  surface.  For  this  purpose  a  one-pint  sight-feed 
lubricator  should  be  fitted  on  the  main  steam  pipe.  A  i/2-in.  or  a  3/4-in.  valve 
should  be  placed  on  the  lower  end  of  the  steam  pipe,  near  the  pump,  to  blow 
out  any  water  when  starting.  A  check  valve  should  be  placed  in  the  water 
column  immediately  above  the  air  vessel,  or,  failing  this,  a  small  pipe  connec- 
tion and  valve  to  empty  the  column  when  it  is  required  to  open  the  water  end 
for  repairs. 

All  bends  or  sharp  angles  should  be  avoided  in  the  water  column.  At  the 
top  of  the  shaft  or  wherever  the  water  is  delivered  a  T  should  be  placed  so  as  to 
give  free  exit  to  the  air. 

A  spare  pump  of  a  similar  type  should  be  kept  in  working  order  at  the  surface 
ready  to  lower  in  case  of  a  bad  breakdown.  Metal  valves  and  seatings  are  not 
suitable  for  gritty  water  and  in  the  case  of  rubber-composition  valves  no  time 
should  be  lost  in  turning  or  changing  them  if  they  are  in  any  way  leaky.  It  is 
poor  economy  to  continue  pumping  with  defective  suction  or  delivery  valves.  A 
good  stock  of  these  should  be  kept  on  hand,  and  as  many  spare  working  parts  as 
possible. 

As  the  water  is  lowered,  the  different  working  levels  should  be  thoroughly 
explored  to  see  that  no  bodies  of  water  have  been  held  back  by  falls  of  ground 
or  other  causes.  Water  so  dammed  is'  liable  to  break  away  later  and  cause 
damage,  besides  endangering  the  lives  of  the  men  in  the  shaft. 

It  is  wise  to  keep  under  the  head  specified  by  the  makers  and  when  this 
limit  has  been  reached  the  pump  should  be  securely  fixed  near  a  level  in  which  a 
tank  should  be  made  either  by  damming  a  portion  of  the  level  with  concrete  or 
by  cutting  out  the  floor  or  side.  Another  pump  should  then  be  installed  to  con- 
tinue the  work  deeper.  The  steam  piping  should  be  large  enough  to  supply 
the  number  of  pumps  considered  necessary  to  unwater  the  mine,  and  it  is  better 
to  put  this  in  at  the  beginning  and  save  the  trouble  of  changing  later  on.  A  book 
should  be  kept  by  the  pumpmen  in  which  should  be  noted:  The  running  time; 
stoppages;  causes;  and  the  depth  the  water  is  lowered  in  each  shift. 

Another  system  of  unwatering  old  workings  is  to  sink  a  shaft  in  virgin 
ground  to  a  depth  below  the  level  of  the  bottom  of  the  old  workings,  and  tapping 
the  water  by  a  drill  hole  which  is  plugged  with  a  special  form  of  plug  and  valve. 
The  water  is  then  under  control,  and  can  be  drained  into  the  sump  of  the  new 
shaft  and  pumped  to  surface.  This  system  requires  a  large  outlay  of  capital, 
but,  is  often  advisable,  especially  in  the  case  of  extensive  and  dangerous 
workings, 

The  Sinking  Pump  and  Its  Troubles  (By  M.  T.  Hoster)  .—In  sinking  wet 
shafts,  both  vertical  and  inclined,  one  of  the  most  important  problems  con- 
fronting the  engineer  is  to  keep  the  bottom  of  the  shaft  so  free  from  water  as  to 
enable  the  miners  to  do  their  work  efficiently.  The  sinking  of  many  shafts, 
especially  in  remote  districts  where  a  few  days  are  required  to  get  supplies,  is 


PUMPING  AND  DRAINING  311 

accompanied  by  far  too  many  temporary  shutdowns  on  account  of  not  being  able 
to  keep  the  water  down  low  enough  for  the  men  to  work. 

Sinking  pumps  and  bailing  skips,  or  buckets,  are  the  most  common  means  of 
keeping  the  water  low.  For  prospecting  a  new  property,  sinking  a  compartment 
shaft,  or  where  but  little  water  is  encountered,  the  bailing  skip  has  the  advantage 
over  the  sinking  pump  for  the  first  few  hundred  feet;  but  for  single-compart- 
ment shafts  or  where  considerable  water  is  met  with,  the  pump  is  by  far  the 
better,  especially  as  the  shaft  gets  deeper. 

For  use  in  inclined  shafts  the  pump  rests  on  its  lower  side;  therefore  it  will 
be  found  best  to  take  off  the  hanger  irons.  If  they  are  simply  turned  so  that 
the  bent  arms  stand  up,  trouble  will  be  encountered  later  in  case  the  cylinder 
head  must  be  taken  off.  For  vertical  shafts  the  pump  is  hung  from  the  ring  or, 
in  timbered  shafts,  from  the  hangers.  If  a  hose  is  used  for  suction  it  should  be 
tightly  wound  with  1/4-  or  i/2-in.  rope  to  prevent  its  being  cut.  The  foot  valve 
at  the  end  of  the  suction  hose  should  always  be  protected  by  a  good  strainer;  it 
takes  but  little  time  to  wrap  some  mosquito  wire  around  this,  and  such  a 
strainer  may  save  much  trouble  by  preventing  chips  of  wood  or  the  like  from 
getting  into  the  water  valve  chest. 

Inside  the  valve  chest  are  two  sets  of  valves  of  two  valves  each;  the  upper  are 
the  exhaust  valves,  the  lower  the  suction  valves.  These  are  made  of  soft-rubber 
set  in  brass  seats  and  mounted  centrally  on  brass  valve  rods.  Each  valve  is 
forced  against  its  valve  seat  by  its  own  spring.  The  priming  valves  in  the  cover 
act  as  a  bypass  over  the  exhaust  valve  beneath  them.  The  trouble  experienced 
with  these  sinking  pumps  can  generally  be  found  in  this  valve  chest  or  in  the 
suction  hose  and  its  foot  valve. 

In  case  of  trouble,  hold  open  one  of  the  suction  valves  and  pour  water  down 
the  suction  hose.  If  it  fills  up  and  remains  full  it  is  evident  that  all  is  in  good 
condition  below.  If  the  water  leaks  out  examine  the  entire  pipe;  the  smallest 
leak  will  cause  much  trouble.  Hold  the  foot  valve  above  water  and  pour  water 
in  above  to  ascertain  whether  a  new  foot  valve  is  required.  Foot-valve  leather 
should  always  be  kept  on  hand. 

If  the  suction  valve  and  foot  valve  are  in  good  condition  the  trouble  is  prob- 
ably in  the  valve  chest.  Be  sure  that  the  gasket  under  the  cover  is  good  or  else 
air  will  leak  in.  If  the  priming  valves  leak  when  closed,  the  pump  will  churn  its 
water  from  the  exhaust-valve  chamber  to  the  suction-valve  chamber  and  will  not 
throw  water  up  the  shaft.  To  detect  this,  close  the  priming  valves  and  try  to 
blow  through  them;  if  they  leak,  new  gaskets  (preferably  leather)  may  remedy 
the  leak  or  else  new  valves  are  required.  I  think  it  best  if  these  valves  are  kept 
tightly  closed  at  all  times  .and  the  pump  primed  as  will  be  described  later. 

A  sinking  pump  always  handles  muddy,  gritty  water  which  is  bound  to  cut 
the  priming-valve  seats  if  the  valves  are  opened  to  let  the  water  through.  The 
soft-rubber  valves  often  become  worn  or  cut  along  the  edges,  letting  the  water 
pass  back  between  the  valves  and  their  seats;  hence  very  little  water  will  go  up 


312 


HANDBOOK  OF  MINING  DETAILS 


the  shaft.  To  remedy  this,  pull  out  the  valve  rod  and  take  the  valve  and  cap  out. 
The  valve  can  be  turned  over  on  its  cap,  but  after  both  sides  are  worn  a  new 
valve  is  needed. 

The  dirt  and  grit  in  the  water  will  in  time  wear  the  valve  rods  and  caps  also, 
the  result  being  that  the  caps  become  too  loose  on  the  rods  (Fig.  i)  and  water 
will  rush  back  past  the  valves  through  the  space  a.  (References  are  to  Fig.  225.) 
In  one  case  where  the  sinking  pump  would  not  work,  nearly  the  whole  pump  was 
overhauled  and  still  it  would  not  throw  water.  Finally  new  rods  and  caps  were 
put  in  and  the  pump  has  worked  well  ever  since.  Only  under  severe  conditions 
will  new  valve  seats  or  springs  be  needed.  The  packing  boxes  should  be  kept 
in  good  condition. 

The  air  (or  steam)  end  of  the  pump  will  probably  never  give  much  trouble, 
but  to  take  out  the  reverse  valves  at  times  and  blow  air  (or  steam)  through  will 


Discharge 


Air  Cylinder 

FIG.  1  FIG.  2 

FIG.  225. — VALVE  AND  COLUMN  PIPE  OF  SINKING  PUMP. 

be  of  benefit.  An  inexperienced  pumpman  will  often  blame  his  troubles  on  the 
air  end  and  thereby  make  a  big  mistake.  The  following  repair  parts  should  al- 
ways be  kept  on  hand  and  should  be  bought  with  the  pump ;  foot-valve  leather, 
two  priming  valves,  four  valve  caps,  two  valve  rods,  good  sheet-rubber  packing 
(i/8-in.),  packing  for  the  boxes  (air  and  water). 

The  column  pipe  should  be  fitted  up  as  is  shown  in  Fig.  2,  with  a  check 
valve  a,  priming  pipe  and  valve  b  and  bypass  c  around  the  check  valve.  The 
check  valve  relieves  the  pump  valves  of  the  back  water  pressure,  and  the  bypass 
is  advantageous  for  starting  the  pump.  To  start  pumping,  open  both  b  and  c, 
running  the  pump  slowly.  The  water  column  being  full  of  water,  enough 
water  will  flow  through  c  to  prime  the  pump  without  the  priming  valves  being 
open.  After  the  pump  starts  throwing  water  out  at  b,  close  c  and  keep  pumping 
into  the  sump,  through  b,  until  all  air  has  been  pumped  out.  Then  close  b 
while  pumping  and  the  pump  will  take  its  head  slowly.  Should  the  column 
pipe  be  empty,  water  can  be  poured  in  at  b. 


PUMPING  AND  DRAINING  313 

Unwatering  a  Mine  with  Electric  Turbine  Pumps  (By  Percy  E.  Barbour). 
—The  unwatering  of  the  Columbus  Consolidated  mine,  at  Alta,  Utah,  in  the 
summer  of  1911  was  an  interesting  work.  This  shaft  is  very  wet,  and  has  been 
flooded  several  times,  and  on  one  occasion  was  unwatered  at  an  expense  of 
about  $30,000.  On  the  last  occasion  the  expenditure  of  such  a  sum  was  prohib- 
itive, yet  the  mine  had  to  be  unwatered.  Bids  were  asked  for  from  contractors, 
and  E.  G.  Stobel,  of  Salt  Lake  City,  who  had  just  returned  from  a  six  months' 
trip  to  European  turbine-pump  plants,  undertook  the  contract  for  about  one- 
fifth  of  the  previous  cost,  his  price  to  cover  the  cost  of  the  pumps,  which  he 
designed  and  had  built  under  his  direct  supervision  in  Salt  Lake  City. 

The  mine  is  opened  by  a  tunnel,  at  the  end  of  which  is  an  incline  shaft  dip- 
ping about  45°  to  the  40o-ft.  level.  Down  to  the  i5o-ft.  level  the  shaft  is  a  single- 
compartment  5X6  ft.;  from  the  150-  to  the  4oo-ft.  level  the  shaft  has  two  5X6- 
ft.  compartments.  Between  the  100-  and  the  i  $o-f  t.  levels,  the  shaft  had  squeezed 
until  the  maximum  opening  left  was  38  in.  The  pumps  had  to  be  built  to 
pass  through  this  small  space. 

Two  specially  designed,  German-type,  high-efficiency  turbine  pumps  were 
used,  one  a  single  stage  and  the  other  a  two-stage  pump.  The  former  was 
direct  connected  to  a  Westinghouse,  vertical,  75-h.p.  alternating-current  motor 
running  at  1720  r.p.m.  The  other  pump  was  direct  connected  to  a  5o-h.p., 
horizontal  Bullock  motor,  transformed  to  a  vertical,  and  run  at  850  r.p.m.  Two 
pumps  were  used  in  order  that  the  old  motors  on  hand  at  the  mine  could  be  used, 
and  thus  reduce  the  cost  of  the  pumping  installation. 

The  single-stage  pump  was  used  as  a  sinker,  and  was  set,  together  with  its 
motor  and  starting  box,  on  a  steel  frame  on  trucks  to  run  down  the  skipway  in  the 
shaft,  and  was  handled  to  the  2Oo-ft.  level  by  the  hoisting  engine  and  cable. 
Below  this  level  a  chain-block  was  used,  and  the  pump  was  lowered  at  5-ft.  inter- 
vals. When  the  water  had  been  pumped  out  to  the  20o-ft.  level,  the  two-stage 
pump  was  installed  as  a  station  pump,  and  thereafter  the  single-stage  sinker  dis- 
charged into  the  suction  of  the  two-stage  station  pump.  A  sollar  was  built  over 
the  shaft  here,  and  mining  on  this  level  immediately  resumed. 

The  suction  pipe  for  the  sinker  was  8  in.  diameter  and  16  ft.  long,  equipped 
with  the  usual  foot  valve  and  strainer.  The  discharge  connection  was  an  inno- 
vation. To  lessen  the  time  and  difficulty  of  making  changes  in  the  piping,  the 
pump  was  connected  to  the  water  column  by  a  short  length  of  6-in.  rubber  hose, 
guaranteed  to  withstand  a  pressure  of  150  Ib.  per  square  inch.  This  required 
piping  to  be  done  only  every  other  time  the  pump  was  lowered. 

The  main  water  column  was  7  in.  diameter,  and  the  average  rate  of  discharge 
was  1200  gal.  per  minute,  by  weir  measurement.  The  total  static  head  was  290 
ft.;  the  friction  head  was  35  ft.  The  average  vacuum  was  equivalent  to  9  in. 
of  mercury.  The  altitude  of  the  mine  was  about  8000  ft.  and  the  corresponding 
barometric  pressure  was  equivalent  to  19  in.  of  mercury.  The  average  effi- 
ciency of  the  single-stage  sinker  was  73  %  and  of  the  two-stage  station  pump 


314 


HANDBOOK  OF  MINING  DETAILS 


77-5%)  both  high  efficiencies  for  that  altitude.  The  work  was  successfully 
done  without  any  delay,  except  the  burning  out  of  one  motor  armature,  which 
got  wet.  The  pumps  were  so  small  and  so  easily  handled  that  only  two  men 
per  shift  were  employed  during  sinking  for  all  labor  required. 

Not  the  least  interesting  feature  of  the  work  was  the  number  of  pumps  recov- 
ered as  the  water  was  pumped  out.  At  the  2oo-ft.  level,  four  air-lift  pumps  of 
various  types,  two  electric-sinkers,  and  one  steam-driven  standard  sinker  were 
recovered.  At  the  3oo-ft.  level,  one  triplex  power  pump  with  75-h.p.  motor, 
one  duplex  steam  pump,  three  centrifugal  pumps,  one  belted  and  two  direct 


FIG.    226. — ARRANGEMENT   OF  AUTOMATIC   CUT-OFF. 

connected,  three  steam  sinkers  and  two  air  lifts  were  recovered.  At  the  400-ft. 
level  were  two  electric  station  pumps,  one  triplex  power  pump,  three  large  sink- 
ing pumps,  and  two  air  lifts;  25  pumps  in  all. 

The  cheap  and  easy  solution  of  this  problem  rested  solely  on  the  minute  de- 
tails given  to  the  design  and  construction  of  the  interior  of  the  pumps,  which 
gave  them  large  capacity  and  high  efficiency.  The  reverse  nozzle  used  reduced 
the  velocity  of  discharge  from  the  pump  vanes  without  the  loss  of  head,  due  to 
the  usual  excessive  eddy  currents  and  friction;  these  particular  features  are 
original  with  the  Germans. 


PUMPING  AND  DRAINING  315 

An  Automatic  Cut-off  for  Electric  Pumps. — The  device  shown  in  Fig.  226 
has  been  in  use  by  Witherbee,  Sherman  &  Co.,  at  Mineville,  N.  Y.,  more  than 
three  years  and  has  operated  satisfactorily.  It  is  used  on  a  three-plunger  electric 
pump  for  handling  mine  water  intermittently  from  a  large  sump.  A  float  A ,  an 
i8-in.  cube,  is  constructed  of  sheet  copper  and  is  placed  in  a  tank  connected 
with  the  sump.  A  cord  is  attached  to  the  float  and  operates  over  a  pulley  with  a 
weight  suspended  on  the  other  end.  The  cord  has  two  clamps  securely  fastened, 
one  above  and  the  other  below  a  slotted  lever  arm.  As  the  water  rises  in  the 
sump  the  float  in  the  tank  will  also  be  elevated.  The  rope  passing  through  the 
slotted  lever  arm  will,  when  the  clamp  comes  in  contact  with  it,  carry  the  arm 
down  to  a  point  past  the  center,  when  the  tension  spring  B  operates  instantly, 
and  thus  closes  the  circuit,  which  starts  the  motor  and  pump.  As  the  water  is 
lowered,  the  cord  is  reversed  and  the  lever  is  driven  past  the  center  when  the 
spring  again  acts  automatically  and  opens  the  switch.  The  scheme  here  used 
is  in  connection  with  an  oil  switch,  yet  could  be  used  with  an  air  switch  when 
using  only  a  small  current,  or  with  carbon  contacts.  However,  for  heavy 
current  the  oil  switch  should  be  used.  The  levers  are  adjustable  so  that  the 
desired  motion  is  given.  The  advantage  of  this  cut-off  is  that  it  acts  automatic- 
ally and  very  little  attention  other  than  an  occasional  oiling  need  be  given  the 
pump.  The  first  cost  of  the  equipment  is  much  less  than  for  the  solenoid  type. 
The  mechanism  is  simple  and  can  be  inclosed  so  that  the  little  moisture  that 
reaches  the  parts  does  not  injure  the  apparatus. 

Pumps  for  Fire  Protection  (By  A.  W.  Newberry). — At  the  Belen  mine  of 
the  Sierra  Mining  Co.,  Ocampo,  Chihuahua,  Mexico,  a  simple  and  effective 
means  of  fire  protection  was  made  necessary  by  the  presence  of  a  large  quantity  of 
dry  pine  timber  in  one  of  the  main  haulage  ways.  A  Smith- Vaile,  8X5X  lo-in. 
duplex  pump,  situated  on  the  95o-ft.  level,  handled  all  the  mine  water  from  a 
main  sump.  The  water  level  was  kept  within  4  ft.  of  the  station,  so  as  to 
provide  sufficient  water  in  case  of  fire.  The  pump,  which  was  supplied  with 
air  at  90  Ib.  pressure,  could  raise  50  gallons  per  minute  against  a  head  of  185  ft. 
To  turn  this  water  into  the  mine,  a  2-in.  pipe  was  provided,  so  as  to  connect  the 
discharge  end  of  the  pump  with  the  main  air  line  to  the  drills,  as  shown  in 
Fig.  227.  The  valve  shown  in  this  line  at  A  was  kept  closed,  and  the  valve  in 
the  main  air  line  B  was  left  open  to  allow  the  passage  of  air.  In  case  of  fire,  the 
valve  B  could  be  closed;  the  release  at  C  opened  to  bring  the  air  in  the  line  down 
to  atmospheric  pressure,  and  the  pump  started,  if  not  running,  by  opening  the 
valve  D.  If  necessary,  the  pump  could  be  quickly  primed  at  E.  As  soon  as 
the  valve  B  was  closed,  the  pumpman  signalled  the  men  at  the  working  face  by 
striking  the  pipe.  These  men  then  proceeded  to  disconnect  the  pipe  at  a  point 
as  near  as  possible  to  the  fire,  unions  being  provided  every  120  ft.  for  this  pur- 
pose. Over  each  union  was  hung  a  hose  connection,  and  one  5o-ft.  armored 
hose  was  kept  in  the  station  for  use  in  case  the  hose  in  the  face  could  not  be 
reached.  As  soon  as  the  hose  was  connected,  the  pipeman  signalled  by  striking 


316  HANDBOOK  OF  MINING  DETAILS 

the  pipe  twice,  and  the  pumpman  opened  the  valve  A,  allowing  water  under  185 
ft.  head  to  flow  through  the  air  line.  This  arrangement  obviated  the  necessity 
of  a  valve  in  the  discharge  column,  and  allowed  all  excess  water  to  escape 
through  the  latter. 


FIG.    227. — PUMP   CONNECTED   TO  AIRLINES    FOR   FIRE    SERVICE. 

Repairing  a  Cracked  Pump  Cylinder. — A  cracked  pump  cylinder  was 
repaired,  states  F.  H.  Coleman,  in  Power,  by  drilling  a  hole  at  one  end  of  the 
crack  and  tapping  for  a  3/8-in.  plug.  Another  hole  was  then  drilled  close  to 
the  first,  the  drill  extending  into  the  first  plug  about  1/8  in.  The  second  hole 
was  then  tapped  and  plugged,  and  the  method  continued  until  the  crack  was 
covered.  It  was  then  smoothed  off  with  a  file  and  calked.  Straps  3/8  in. 
thick  used  with  iron  cement  further  secured  the  job.  The  pump  has  been 
running  for  some  time  with  a  no-lb.  pressure  without  signs  of  leaking. 

Air  Escape  on  Small  Pump  Columns. — At  some  of  the  mines  in  the  Joplin 
district  the  pumps  are  operated  intermittently.  The  water  is  pumped  into  the 
column  pipe  in  the  shaft  and  at  the  surface  is  discharged  into  a  pipe  through 
which  it  flows  to  the  mill  pond.  Where  the  difference  in  elevation  between  the 
collar  of  the  shaft  and  the  water  in  the  pond  is  only  a  few  feet  and  the  pipe  is 
only  about  3  in.  in  diameter  it  is  the  custom  to  use  a  tee  at  the  top  of  the  pump 
column.  The  side  leg  of  this  tee  is  connected  to  the  surface  pipe,  and  a  short 
piece  of  pipe  is  screwed  into  the  upper  leg.  The  length  of  this  short,  vertical 
extension  of  the  column  above  the  tee  is  sufficient  to  prevent  any  water  being 


PUMPING  AND  DRAINING  317 

discharged  over  its  top.  The  object  of  using  the  tee  and  the  short  vertical 
extension  of  the  column  is  to  permit  air  to  escape  at  the  top  of  the  column  which 
otherwise  would  have  to  flow  through  the  surface  pipe. 

Concrete  Water  Column. — At  one  of  the  shafts  of  the  Continental  Zinc 
Co.,  Joplin,  Mo.,  the  water  contains  so  much  sulphuric  acid  that  an  iron  water 
column  will  not  last  more  than  30  days.  The  quantity  of  water  to  be  pumped 
is  about  800  gallons  per  minute.  The  water  contains  1/4  oz.  sulphuric  acid  per 
cubic  foot  and  3  1/4  oz.  soluble  sulphates.  A  hole  16  in.  in  diameter  was 
drilled  from  the  surface  with  a  Star  No.  23  drill,  to  a  depth  of  208  ft.  A  lo-in. 
casing  was  then  inserted,  leaving  an  annular  space  of  3  in.  between  the  pipe  and 
the  solid  ground.  This  annular  space  was  then  filled  with  neat  cement  and 
allowed  to  set,  making  a  solid  concrete  tube  from  the  surface  to  the  pump 
station.  The  pump  used  was  a  12X24-^1.  Scran  ton  lined  with  brass.  A 
flexible  joint  with  brass  discharge  connected  with  the  bottom  of  the  cement 
column.  The  cement  column  was  used  for  several  months  until  a  cave  in  the 
mine  destroyed  it. 

Expansion  Joint  for  Pipe  Lines  (By  C.  L.  Edholm). — At  a  Western  mine, 
a  U-shaped  pipe  is  used  in  a  long  pipe  line  for  steam  to  take  up  the  expansion 
and  contraction  caused  by  changes  in  temperature.  The  bend  is  supported  by 
iron  posts  in  such  a  manner  that  the  pipe  can  slide  freely  over  the  supports  in 
contracting  or  expanding.  The  device  not  only  takes  care  of  all  the  expansion 
in  the  pipe  line,  but  also  reduces  the  vibrations  that,  if  not  checked  in  some  way, 
would  quickly  cause  leakage  at  all  the  joints  in  the  line. 

[This  device  is  a  very  common  and  extensively  used  joint  for  taking  care  of 
expansion  in  pipe  lines.  A  similar  device  consists  in  bending  a  pipe  into  a 
complete  circle  of  as  great  a  radius  as  practicable.  The  circular  pipe  has  an 
advantage  over  the  U-pipe  in  that  it  can  be  hung  on  a  single  support;  the  re- 
sistance to  the  flow  of  fluid  is  probably  greater  in  the  U-pipe  than  in  the  circular 
pipe. — EDITOR.] 

Utilizing  Water  in  Mines. — Where  it  is  necessary  to  drop  water  a  hundred 
feet  or  more  to  a  pumping  level,  it  can  be  utilized  to  furnish  power  by  conducting 
it  through  tight  pipes  instead  of  allowing  it  to  find  its  own  course  through  stopes, 
raises,  etc.  One  Cceur  d'Alene  mine  uses  such  power  to  drive  a  fan,  and  an- 
other drives  a  generator  which  supplies  electric  light  to  six  stations  of  the  mine. 

Pump  Station  at  Leonard  Mine,  Butte.— The  pumps  for  handling  all  of 
the  water  from  the  Boston  &  Montana  company's  mines,  and  from  some  of  the 
mines  of  the  Butte  Coalition  company,  are  stationed  on  the  i20o-ft  level  of  the 
Leonard  mine.  The  new  pump  station  is  situated  about  150  ft.  to  the  south  of 
the  No.  i  Leonard  shaft,  the  old  pump  station  being  close  to  the  shaft.  The 
No.  i  Leonard  shaft  serves  as  an  airway.  Between  the  No.  i  and  the  No.  2 
shafts,  the  latter  of  which  is  the  main  hoisting  shaft  of  the  mine  at  the  present 
time,  separate  parallel  drifts  are  run  for  haulage- ways  and  for  carrying  the  air, 
steam  and  water  lines,  and  electric  cables. 


HANDBOOK  OF  MINING  DETAILS 


The  pumping  equipment  in  the  new  station  comprises  three  6oo-gal.,  five- 
throw,  electrically  driven  pumps,  one  of  which  is  of  Aldrich  and  two  of  Nord- 
berg  build.  The  pumps  are  7Xi2-in.  size  and  are  each  driven  at  60  strokes 
per  minute  by  two  i5o-h.p.,  440- volt,  i8o-amp.  motors  run  at  495  r.p.m.  In  the 
old  station  there  is  a  i5oo-gal.  auxiliary  steam  pump  and  a  smaller  one  with 
a  capacity  of  about  600  gal.  per  minute. 

The  construction  and  timbering  of  the  station  is  particularly  interesting.  It 
is  built  with  an  idea  of  providing  ample  space  and  in  such  a  manner  as  to  assure 
permanence.  Provision  against  the  crushing  of  timbers  and  caving  of  the  roof 


lh  Sheet  Steel 


Block 


Rail  for  Traveling 
Chain  Blocks 


Discharge  for 
Accumulated  Dirt 


---4- 


Car 


FIG.    228. — TIMBER   SET   IN    PUMP   STATION,    LEONARD    MINE,    BUTTE,    MONT. 

was  especially  necessary,  for  as  stated,  the  pumps  in  this  station  handle  prac- 
tically all  of  the  water  from  a  number  of  the  mines  of  two  of  the  large  Butte 
companies,  hence,  the  stopping  of  the  pumps  for  any  length  of  time  would  entail 
a  large  loss. 

The  station  is  cut  out  about  35X75  ft.  and  30  ft.  high  in  the  clear.  Fig.  228 
shows  the  scheme  of  timbering  employed.  The  caps  reach  entirely  across  the 
station  and  are  supported  at  their  ends  by  posts  and  also  at  points  4  ft.  from  the 
ends  by  auxiliary  posts.  Thus  along  each  side  of  the  station  there  are  two  rows 
of  posts.  Angle  braces  are  used  above  the  inner  row  to  give  added  support  to 
the  roof  of  the  station,  which  is  trussed,  the  peak  being  9  ft.  above  the  center  of 


PUMPING  AND  DRAINING  319 

the  caps.  (Above  pumps,  caps  are  cut  out  and  horizontal  angle  braces  used.) 
At  the  point  of  their  abutting,  the  caps  are  held  firmly  in  place  by  bolts  through 
cover  plates  of  i  i/2-in.  sheet  steel.  The  plate  over  the  joint  of  the  roof  mem- 
bers extends  16  in.  down  each  side.  The  station  sets  are  constructed  throughout 
of  i4X  i4-in.  Oregon  fir  timber;  sets  are  5  ft.  center  to  center. 

By  giving  the  station  a  peaked  roof  considerable  extra  excavation  is  necessi- 
tated and  additional  timber  is  required.  The  added  cost  this  entails,  is,  however, 
more  than  counterbalanced  by  the  safety  from  caving  that  is  assured  by  the  addi- 
tional strength  given  to  the  timber  framing.  In  a  similar  station  with  a  flat  roof 
it  was  necessary  to  clear  out  the  caved  material  above  the  caps  each  year.  The 
station  described  has  already  stood  for  three  years  and  it  has  not  yet  been  neces- 
sary to  clear  away  any  debris ;  flooring  is,  however,  built  over  the  caps  to  catch 
any  material  that  caves,  and  an  opening  is  left  between  the  rows  of  posts  along 
one  side  for  the  discharge  of  any  caved  material.  Tracks  are  laid  along  this 
aisle  for  cars  to  handle  the  dirt. 

Under  the  floor  of  the  station  is  built  a  small  concrete-lined  tank,  3  X  20  ft. 
and  8  ft.  deep,  about  which  the  pumps  are  grouped.  The  pump  plungers  all 
draw  directly  from  this  small  sump,  and  a  feeder  20  in.  wide  and  8  ft.  deep  con- 
nects this  to  the  main  tank,  which  is  excavated  in  the  solid  rock  to  one  side  of  the 
station  and  has  a  capacity  of  25,000  gallons.  The  concrete  lining  of  this  larger 
tank  is  2  ft.  thick.  A  great  saving  in  non-corrodible  piping  is  effected  by  having 
the  pump  plungers  draw  directly  from  the  small  pump  tank  and  at  the  same  time 
the  pumps  are  seated  upon  firm  foundations.  It  is  figured  that  the  additional 
cost  necessitated  by  building  the  station  as  described  will  be  more  than  over- 
balanced by  the  saving  effected  in  its  upkeep. 

AIR  LIFTS  AND  EDUCTORS 

Notes  on  the  Pohle  Air  Lift1  (By  W.  S.  Anderson). — The  proportions  of 
piping,  submergence,  etc.,  in  the  Pohle  air  lift  may  be  arrived  at  mathematically, 
basing  the  calculations  on  the  expansion  of  the  air  bubbles  as  they  rise  to  the 
discharge  where  the  head  due  to  the  sum  of  the  water  pistons  above  diminishes, 
and  on  the  usual  formulas  covering  capacities  of  air  and  water  pipes;  but  for 
practical  purposes  in  the  case  of  small  wells  reliable  results  may  be  derived 
from  the  following: 

It  is  found  in  practice  that  the  length  of  pipe  submerged  below  the  normal 
pumping  level  after  the  water  has  fallen  should  range  from  30  to  60  per  cent,  of  the 
total  length  of  pipe  from  the  bottom  end  to  the  top  of  discharge,  the  greater 
ratio  of  60  %  generally  giving  the  greatest  efficiency.  The  air  pressure  should 
vary  from  three-quarters  of  the  pressure  due  to  the  total  lift  for  shallow  wells  to 
six-tenths  for  deep  wells.  It  should  be  such  that  it  will  about  equal  atmospheric 
pressure  at  the  point  of  discharge,  unless  high  velocity  is  desired  at  the  expense 
of  economy.  That  is,  it  should  equal  the  head  in  feet  multiplied  by  0.434  plus 
a  few  pounds  for  friction,  this  latter  depending  on  the  length  of  pipe  and  friction 

1  Reprinted  from  Power,  December,  1909. 


320  HANDBOOK  OF  MINING  DETAILS 

head.  In  this  connection  it  should  be  remembered  that  where  a  central  air 
pipe  is  used  in  drilled  wells,  on  account  of  there  not  being  room  for  the  air  pipe 
outside  of  the  water  pipe,  the  friction  head  is  greater.  If  the  compressor  is  close 
to  the  well,  the  reservoir  should  be  proportioned  to  reduce  all  impulses,  though 
in  the  case  of  a  long  air  line  this  will  to  a  great  extent  take  care  of  itself. 

In  the  case  of  a  large  well  casing,  where  the  inflow  into  the  well  is  small,  or 
where  the  desired  amount  of  water  is  small  in  proportion  to  the  capacity  of  the 
pipe,  the  air  pipe,  if  central,  should  purposely  be  made  large  enough  to  prevent 
blowing,  the  most  desirable  proportion,  as  indicated  by  practice,  being  about 
1:2  for  small  wells  and  1:3  where  the  diameter  of  water  pipe  is  over  2  1/2  in. ; 
or  the  area  of  the  water  pipe  is  about  six  times  the  area  of  the  air  pipe  for  average 
cases.  If  the  air  is  taken  from  shop  air  mains,  where  variable  service  causes  a 
large  variation  in  air  pressure,  and  the  air  is  not  run  through  a  reducing  valve, 
the  sudden  expansion  of  high-pressure  air  at  the  discharge  is  likely  to  cause 
trouble,  if  the  discharge  is  into  a  covered  or  practically  closed  tank.  This  may 
be  relieved  by  putting  a  large-sized  safety  valve  at  any  convenient  bend. 

Assuming  60%  submergence,  the  volume  of  free  air  for  maximum  economy 
may  be  roughly  taken  from  the  following:  For  lifts  of  25  ft.,  13  cu.  ft.  of  air  for 
100  gallons  of  water;  for  lifts  of  75  ft.,  28  cu.  ft.  of  air  per  100  gallons  of  water; 
for  lifts  of  100  ft.,  36  cu.  ft.  of  air  per  100  gallons  of  water;  for  lifts  of  150  ft., 
57  cu.  ft.  of  air  per  100  gallons  of  water;  for  lifts  of  200  ft,  75  cu.  ft.  of  air  per 
100  gallons  of  water. 

With  side  inlets  and  3/4-in.  air  pipes  and  i  i/2-in.  water  pipe,  the  ordinary 
capacity  will  be  about  25  gallons  per  minute,  and  for  larger  wells  the  capacity 
may  be  assumed  as  varying  nearly  but  not  quite  with  the  square  of  the  diameter 
of  the  water  pipe.  For  example,  a  6-in.  water  pipe  will  ordinarily  give  a  flow  at 
fair  economy  of  from  400  to  425  gallons  per  minute.  In  the  case  of  central  air 
pipe  with  3  i/2-in.  casing,  the  output  should  be  about  no  gallons  per  minute, 
or  230  gallons  with  5-in.  pipe,  and  other  sizes  in  proportion.  Generally  speak- 
ing, from  10  to  14  gallons  per  square  inch  of  area  of  water  pipe,  after  deducting 
the  air-pipe  area,  will  be  about  right,  the  smaller  figure  being  used  for  short  lifts 
and  the  larger  figure  for  lifts  of  100  ft  or  over. 

The  matter  of  economy  is  generally  misunderstood  and  most  of  the  claims  of 
high  efficiency  should  be  taken  with  rather  a  liberal  allowance.  While  under 
favorable  conditions  it  may  be  possible  to  approach  70  or  80%  efficiency 
figured  from  the  discharge  back  to  the  indicated  horsepower  of  the  compressor, 
most  of  the  tests  of  ordinary  wells  where  extreme  submergence  is  not  possible 
seem  to  indicate  efficiencies  between  20  and  35%.  It  should  also  be  under- 
stood and  remembered  that  the  air  lift  is  not  well  adapted  to  forcing  water  hori- 
zontally, and  horizontal  discharges  of  over  40  or  50  ft.  should  be  avoided,  ex- 
cept by  discharging  into  a  tank  with  a  gravity  flow  the  rest  of  the  distance. 

Unwatering  Shaft  by  Compressed  Air  (By  Louis  Boudoire). — A  simple 
air  lift  can  be  quickly  set  up  to  unwater  mine  shafts.  Fig.  229  shows  the  arrange- 


PUMPING  AND  DRAINING 


321 


ment  of  the  piping.  In  the  mine  where  it  was  used  40-mm.  and  po-mm.  pipes 
were  at  hand  and,  as  the  necessity  of  unwatering  a  certain  shaft  on  the  property 
was  urgent,  no  time  was  spent  in  an  effort  to  improve  the  efficiency  of  the  appli- 
ance by  tapering  the  ends  of  the  pipes.  Air  was  delivered  at  an  effective  pressure 
of  65  Ib.  per  square  inch;  the  vertical  length  of  the  go-mm.  water  pipe  was  40  m., 
and  its  horizontal  length  300  m.  The  results  were  as  follows:  With  a  submer- 
gence of  30  to  35  m.  and  a  lift  varying  up  to  5  m.  the  output  was  over  200  liters 
per  minute;  with  a  submergence  of  14  m.  and  lift  of  21  m.  the  output  was  50  liters, 


-Water  and  Air 


Compressed 
Air 


90mm. 


40  mm. 


FIG   229. — AIR  LIFT  FOR  UNWATERING  SHAFT. 

and  with  a  submergence  of  n  m.  and  a  lift  of  24m.,  it  was  only  30  liters.  The 
output  decreases,  therefore,  as  the  height  which  the  water  must  be  lifted  in-, 
creases.  Although  the  efficiency  of  the  system  is  not  high,  it  presents  valuable 
advantages  for  emergency  use,  as  it  can  be  quickly  installed,  does  not  require  any 
attention,  oiling  nor,  as  does  a  pump,  adjustment  for  every  7-  to  8-m.  variation 
of  the  head  under  which  it  is  operating.  In  the  case  of  a  deep  shaft  this  appli- 
ance might  be  used  to  assist  the  sinking  pump  which  would  then  have  to  be 
lowered  only  for  every  25-  or  30-01.  reduction  of  the  water  level. 


322 


HANDBOOK  OF  MINING  DETAILS 


PUMPING  AND  DRAINING  323 

Mine  Eductors  (By  Oskar  Nagel) . — The  lifting  of  large  quantities  of  water, 
a  problem  of  great  importance  in  mining,  is  mostly  performed  by  means  of 
pumps.  In  places,  however,  where  the  space  available  is  insufficient  for  the 
installation  of  a  pump,  the  water-jet  eductor,  Fig.  i  (reference  is  to  Fig.  230), 
is  the  proper  machine  to  use.  The  pressure  water  enters  the  eductor  at  P. 
Passing  through  a  nozzle,  it  creates  a  vacuum,  and  raises  the  water  by  suction 
at  5,  discharging  the  entire  volume  of  liquid  at  D.  These  eductors  are  designed 
to  raise  water  by  means  of  high-pressure  water,  and  are  used  as  follows: 

(i).  Water  collecting  at  a  considerable  altitude  is  used  to  raise  water  which 
has  collected  further  down,  both  being  discharged  at  a  medium  level,  thus  per- 
mitting flow  off  through  horizontal  openings  down  a  hillside,  or  to  a  pumping 
engine. 

(2).  In  a  similar  manner  the  water  from  a  condenser  of  an  underground 
pumping  engine  may  be  raised  with  advantage. 

(3).  Even  if  the  pressure  should  have  an  available  head  of  but  a  few  yards, 
it  is  possible  to  effect  a  considerable  suction  which  is  particularly  useful  in 
tunneling. 

Fig.  2  shows  .an  installation  and  illustrates  the  simple  manner  in  which  an 
eductor  may  be  installed  in  the  smallest  possible  space.  E  is  the  eductor,  O  the 
suction  hose,  P  the  main  pump.  Fig.  3  shows  how  in  a  turbine  installation  the 
fall  of  a  river  may  be  utilized  by  means  of  eductors.  Even  with  a  low  fall  the 
eductor  retains  its  capacity  for  high  suction  up  to  16  ft.  and  above. 

The  advantages  of  eductors  for  sinking  shafts  have  caused  their  application 
in  connection  with  high-pressure  pumps.  Fig.  4  shows  such  a  plant.  D  is  the 
discharge,  E  the  eductor,  P  the  pressure  line  from  pump  creating  water  pressure. 
This  method  has  the  following  advantageous  features:  It  is  easy  to  handle  the 
apparatus,  as  only  piping  of  small  diameter  and  small  weights  is  to  be  taken 
into  consideration;  the  small  space  required,  and,  above  all,  the  free  working 
space;  positive  working,  due  to  the  absence  of  moving  parts;  the  apparatus 
works  with  equal  sureness  in  case  the  water  does  not  flow  sufficiently  to  the  shaft. 

Fig.  5  shows  the  eductor  in  a  shaft  taking  the  head-water  from  the  surface 
and  discharging  into  an  upper  gangway.  From  the  flume  H  on  the  surface,  the 
water  flows  to  the  eductor  E  and  lifts  the  water  from  sump  S,  discharging  into 
the  gangway,  or  passage  G. 

These  mine  eductors  are  used  by:  Thomas  Shelton  (Engelbach  Machinery 
Co.),  Leadville,  Colo.;  Compania  de  Santa  Gertrudis,  S.  A.,  Pachuca,  Hidalgo, 
Mexico;  Benito  Juarez  Mines  Co.,  Salinas,  Mexico;  Arizona-Parral  Mining 
Co.,  Denver,  Colorado. 

MINE  DRAINAGE 

Draining  a  Shaft  through  a  Drill  Hole  (By  Lucius  L.  Wittich).— By 
installing  a  deep-well  pump  in  an  8-in  drill  hole,  sunk  7  ft.  from  the  shaft, 
J.  M.  Short,  operator  of  the  Geronimo  mine,  on  a  lease  of  the  Connor  Estate 


324  HANDBOOK  OF  MINING  DETAILS 

at  Ellis ville,  west  of  Joplin,  Mo.,  is  able  to  dispense  with  the  pump  that  he  has 
been  using  in  sinking  the  shaft,  thus  reducing  the  cost  of  sinking  from  $25  to 
$17.50  per  foot,  a  saving  of  $7.50  per  foot.  As  the  shaft  was  70  ft.  deep  when 
the  pumping  arrangements  were  changed  and  as  the  shaft  must  be  sunk  to  a 
depth  of  126  ft.  to  reach  the  ore,  as  indicated  by  the  drill  hole  on  which  the 
shaft  is  being  sunk,  56  ft.  remain  to  be  sunk.  The  total  saving  will  be  $420. 
Deducting  from  this,  $150,  the  cost  of  sinking  the  8-in.  drill  hole  and  installing 
the  deep- well  pump  the  net  saving  in  money  will  be  $270.  Of  course  this  does 
not  include  the  cost  of  the  drill  rig  and  pump  which  were  on  hand.  Had  the 
system  been  adopted  earlier  the  saving  would  be  much  greater. 

But  the  most  important  feature  is  in  the  saving  of  time  in  sinking.  Before 
the  drill-hole  pump  was  placed  in  operation,  the  shaft  was  being  sunk  at  the 
rate  of  5  ft.  per  week;  now  it  is  being  sunk  5  ft.  in  16  hours.  Previously  it 
was  necessary  to  remove  the  pump  after  loading  each  round  of  holes  and  to  re- 
place it  after  blasting,  or,  at  least,  it  was  necessary  to  guard  the  pump  with 
heavy  timbers,  and  even  with  this  precaution  the  machinery  was  almost  in- 
variably damaged  by  the  blasts.  On  this  account  it  was  impossible  to  use 
heavy  blasts  when  the  pump  was  left  in  the  ground.  Now  it  is  possible  to  use 
full  charges  of  dynamite,  and  the  working  ability  of  the  pump  in  the  drill  hole 
near-by  is  not  impaired. 

In  following  a  system  of  this  kind,  adopted  for  the  first  time  in  the  Joplin 
district  by  Short,  it  would  seem  necessary  that  the  shaft  should  be  either  sunk 
through  open  ground,  permitting  free  drainage  of  water  to  the  drill  hole,  or 
that  two  drill  holes  should  be  sunk,  one  squarely  in  the  center  of  the  shaft  and 
the  other  near-by  for  the  pump.  The  latter  is  the  system  followed  by  the  Gero- 
nimo  company.  The  shaft  is  being  sunk  through  hard  limestone  beneath 
which  occurs  the  open  ground  in  which  the  ore  is  found.  Both  holes  penetrate 
the  open  ground,  the  deep-well  pump  having  been  installed  to  a  depth  of 
150  ft.  Care  is  taken  to  keep  open  the  drill  hole  in  the  bottom  of  the  shaft,  for 
through  it  the  water  from  the  shaft  seeps  into  the  lower  open  ground,  thence 
across  the  interventing  space  of  7  ft.  to  the  second  drill  hole,  whence  it  is 
pumped  out.  In  this  manner  the  shaft,  formerly  so  wet  that  the  miners  were 
forced  to  wear  rubber  boots,  is  now  dry  and  the  excavated  rock  is  handled  with 
much  greater  ease. 

Draining  with  Well  Points. — It  is  often  the  case  in  placing  concrete  piers, 
foundations  and  retaining  walls,  that  there  is  a  heavy  influx  of  drainage  water  that 
rapidly  fills  the  pit  dug  for  foundations,  or  accumulating  behind  the  forms  for 
retaining  walls,  rises  to  exert  a  considerable  hydrostatic  pressure  that  may  warp 
the  forms  either  prior  to  or  after  filling  with  concrete.  In  laying  concrete  founda- 
tions supported  on  all  sides,  the  inflowing  water  is  not  of  much  moment  as  the 
concrete  may  be  filled  in  to  displace  the  water,  and  if  there  is  no  heavy  upward 
flow  that  carries  away  the  fine  cement,  a  substantial  foundation  is  obtained.  But 
there  are  many  instances  when  ground  water  is  detrimental  to  both  the  stability 


PUMPING  AND  DRAINING  325 

and  facility  of  making  the  structure,  more  particularly  in  the  case  of  retaining 
walls.  In  laying  brick  or  stone  masonry  in  pits,  such  as  elevator  pits,  the  inflow 
of  water  must  be  controlled  and  usually  the  desire  is  to  draw  the  water  from 
back  of  the  wall  being  built,  i.e.,  between  the  wall  and  face  of  earth  which  the  wall 
is  to  support.  The  problem  of  draining,  while  building  a  wall  that  will  later 
be  impervious  to  water,  may  often  be  satisfactorily  accomplished  by  using  well 
points,  driving  them  down  back  of  the  wall.  A  number  of  such  points  can  be 
attached,  preferably  by  a  flexible  coupling  such  as  a  short  length  of  hose,  to  a 
main  leading  to  the  suction  chamber  of  a  pump.  The  well  points  are  made  of 
i-,  i  i/  2-  or  2-in.  pipe  of  suitable  length,  to  one  end  of  which  a  solid  iron  or  steel 
driving  point  has  been  welded.  Above  the  point  the  pipe  is  drilled  with  many 
small  holes  for  a  foot  of  its  length  to  make  a  strainer.  In  driving  the  pipes,  a 
steel  or  iron  bar,  just  a  trifle  smaller  than  the  diameter  of  the  well  point  and  a 
foot  longer,  which  at  a  point  about  14  in.  from  the  end  has  been  upset  enough  to 
make  it  a  little  larger  than  the  pipe,  is  placed  in  the  pipe,  and  the  point  is  driven 
by  sledging  the  upper  end  of  the  bar.  When  the  point  is  driven  to  the  desired 
depth  the  bar  is  withdrawn.  When  first  used  the  pump  draws  considerable 
sand  through  the  pipe  but  gradually  the  gravel  and  bits  of  rock  too  large  to  pass 
the  strainer  form  a  coarse  filter  that  not  only  prevents  much  sand  from  entering 
the  pipe  but  gives  freer  passage  for  the  entering  water. 

Draining  an  Ore  Chute  (By  Arthur  O.  Christensen) . — At  the  Enterprise 
mine,  Gunnison  County,  Colo.,  a  raise  is  being  driven  from  No.  3  to  No.  2  tunnel, 
800  ft.  above.  The  raise  is  a  three-compartment  incline  following  the  vein. 
The  man  way  is  in  the  middle  with  skipway  and  chute  on  either  side.  The  whole 
is  cribbed  with  8-in.  timber.  At  every  100  ft.  a  level  is  driven  on  the  vein  in 
each  direction.  As  the  work  progressed  more  or  less  water  was  encountered  on 
the  levels.  This  flowed  to  the  stations,  and  as  no  provision  had  been  made  for 
carrying  off  the  water,  it  found  its  way  into  the  chute.  The  quantity  of  water 
was  not  large,  but  was  enough  to  keep  the  dirt  in  the  chute  at  just  the  proper  con- 
sistency to  stick  there,  the  dirt  being  largely  of  a  clayey  character.  The  objection 
offered  to  making  any  provision  for  carrying  off  the  water  from  the  levels  was 
that  there  was  no  room  in  the  raise  to  put  any  conduit  for  it.  The  ladder  and 
suction  pipe  filled  all  the  space  which  could  be  spared  in  the  manway. 

At  intervals  of  about  a  foot  holes  were  bored  from  the  manway  into  the  chute. 
By  the  use  of  drills  and  a  bent  rod  it  was  possible,  with  sufficient  labor,  whenever 
the  chute  became  "hung  up,"  which  was  the  greater  part  of  the  time,  to  get  it 
down  by  working  through  these  holes.  This  was  expensive  and  laborious.  At 
each  level  a  length  of  the  suction  pipe  was  removed  and  a  T  inserted,  having  a 
5-in.  side  opening.  A  section  of  5-in.  pipe  was  carried  through  the  back  of  the 
raise  into  the  station,  entering  it  a  little  below  the  bottom.  This  was  con- 
nected to  a  trough,  as  shown  in  Fig.  231.  The  water  from  the  levels  is  run  into 
the  trough  and  carried  by  it  into  the  suction  line,  through  which  it  falls  into  a 
barrel  provided  at  the  bottom  of  the  raise. 


326 


HANDBOOK  OF  MINING  DETAILS 


By  having  the  water  fall  through  the  airway  the  flow  of  air  has  been  notice- 
ably increased,  and  the  water,  instead  of  being  trammed  out  with  the  dirt,  now 
helps  to  run  the  compressor  which  supplies  power  for  the  mine.  Compara- 
tively little  difficulty  is  now  experienced  by  the  dirt  being  hung  up,  as  the  only 
water  entering  the  chute  is  what  runs  in  from  the  breast  of  the  raise.  What 
hang-ups  do  occur  are  readily  taken  care  of  by  providing  the  following  arrange- 
ment in  the  partition  between  the  manway  and  the  chute: 


FIG.    231. — DRAINAGE    SCHEME   FROM   STATION   TO    SUCTION    PIPE. 

Slits  2X4  in.  are  cut  between  alternate  timbers.  Over  the  slit  is  nailed  a 
piece  of  inch  board  about  5  X  8  in.,  by  driving  one  nail  at  the  top  so  the  door  thus 
formed  can  be  swung  up  when  it  is  desired  to  look  in  or  to  poke  hung-up  dirt. 
These  doors  keep  small  rocks  and  dirt  from  flying  into  the  manway.  The  tim- 
bers now  being  framed  are  made  with  a  groove  across  the  middle  of  one  edge 
2X2  in.  on  the  manway  side  and  6X4  on  the  chute  side,  as  shown  in  Fig.  232. 


FIG.    232. — METHOD    OF   CUTTING   TIMBERS. 

When  these  partition  pieces  are  put  in  they  form  a  slit  2  X  4  in.  on  the  manway 
side  and  6  X  8  in.  on  the  chute  side,  the  slits  being  between  every  other  partition 
piece.  By  having  openings  this  size  and  shape  a  hang-up  is  easily  pried  down 
by  working  from  the  manway. 

The  chute  in  question  is  2  ft.  8  in.  X  3  ft.  8  in.,  cribbed  solidly,  but  not  lined. 
The  dip  of  the  raise  varies  between  60  and  70°.  This  chute  seems  to  be  too 
small,  for  even  dry  dirt,  after  piling  up  in  it,  has  to  be  barred  down  occasionally. 


PUMPING  AND  DRAINING 


327 


A  chute  of  this  dip  should  be  lined  on  the  bottom  to  prevent  wear  and  hanging 
of  the  dirt.  Planks  2  in.  or  4  in.  thick,  laid  longitudinally,  or  still  better,  sheet 
iron,  make  good  lining  when  well  supported  from  underneath. 

Draining  Gravity  Planes. — The  best  plan  to  drain  a  gravity  plane  and 
keep  the  track  ties  in  place  is  to  lay  a  line  of  tile-pipe  with  properly  cemented 
joints  on  one  side  of  the  track.  All  the  water  that  can  be  diverted  from  the  head 
of  the  plane  should  pass  down  this  drain.  Several  Y's  should  be  put  in  the  line 
and  6-in.  branches  run  from  these  under  the  track.  These  branches  should  be 
cemented  on  the  under  half.  The  upper  half  should  be  left  uncemented  so  as  to 
drain  the  roadbed  and  the  ditches  in  which  the  branch  pipes  are  laid  covered 
with  broken  stone. 


.  Concrete  Block 


FIG.    233. — DRAINING  A   GRAVITY   PLANE   WITH  SEWER   PIPE. 

Some  planes  are  laid  with  anchored  wood-silts  into  which  the  cross-ties  are 
notched.  The  notching  results  in  speedy  rotting  of  the  timber  and  the  expense 
of  such  a  method  is  considerable.  The  use  of  long  ties  common  to  both  tracks 
as  shown  in  Fig.  233  is  recommended  by  Coal  Age,  but  perhaps  the  best  security 
and  the  cheapest  is  the  use  of  a  haulage  rope  spiked  to  the  end  of  ties  and 
secured  to  a  heavy  timber,  masonry  or  concrete  support  at  the  head  of  the  plane. 
If  the  plane  is  long,  two  or  three  of  these  may  be  necessary  so  as  to  divide  up  the 
expansion  from  heat.  Old,  discarded  ropes  will  do,  and  a  heavy  coat  of  tar 
will  prevent  them  from  rusting  away;  this  coat  being  applied  before  and  after 
their  attachment  to  the  ties. 


HANDBOOK  OF  MINING  DETAILS 


FIG.    234. — CAST   IRON   GATE   FOR  MINE  DRIFTS. 


PUMPING  AND  DRAINING  329 

Gate  for  Controlling  Mine  Water. — A  gate  used  for  controlling  water  flow 
in  mines  is  shown  in  Fig.  234.  This  particular  gate  was  used  at  Flat  River, 
Mo.,  to  protect  pumps  and  mine  workings  from  sudden  flows  of  water.  The 
gate  is  of  cast  iron,  i  1/2  in.  thick,  with  longitudinal  and  cross  ribs  6  in.  high  and 
i  1/4  in.  thick.  The  door  is  5  ft.  7  in.  wide,  and  6  ft.  7  in.  high  and  has  an  8-in. 
opening  in  the  lower  left-hand  corner  to  which  a  pipe  and  valve  may  be  attached. 
Near  this  opening  is  a  small  wheel  to  support  a  portion  of  the  weight  of  the  door, 
and  thus  relieve  the  hinges  of  such  a  large  burden.  The  door  closes  against 
a  cast-iron  frame  C  which  is  securely  cemented  into  the  wall  of  the  drift.  A 
groove  is  cast  in  one  side  of  the  frame,  and  a  piece  of  i-in.  square  rubber  packing 
is  inserted  and  held  in  place  by  a  small  brass  strip.  The  door  closes  against  the 
rubber  packing,  and  is  so  hung  that  the  pressure  of  the  water  from  within  will 
hold  it  shut.  In  order  to  open  the  gate  it  is  necessary  to  open  the  valve  and 
allow  the  water  to  flow  out,  thus  relieving  the  pressure. 

Stopping  the  Flow  of  Water  from  a  Drill  Hole.— Several  years  ago  a 
bore-hole  drilled  from  the  No.  7  plat  of  the  Armstrong  shaft,  in  the  Great  Fin- 
gall  mine,  Western  Australia,  encountered  a  flow  of  6000  gallons  per  hour  of 
salt  water,  at  a  depth  of  500  ft.  The  bore-hole  inclined  27°  from  the  horizontal 
and  attained  a  total  depth  of  747  ft.  When  drilling  operations  were  concluded 
it  was  decided  to  control  the  flow  of  water,  and  the  following  method,  described 
by  G.  C.  Klug  in  the  Journal  of  the  Western  Australia  Chamber  of  Mines,  was 
employed: 

A  piece  of  i  i/2-in.  steam  pipe  5  ft.  long  was  tapered  for  half  its  length  from 
its  full  diameter  at  the  middle  to  i  11/16  in.  at  the  end,  the  metal  at  this  point 
being  1/32  in.  thick;  the  other  end  of  the  pipe  was  threaded  to  receive  a  i  i/2-in. 
plug-cock.  The  tapered  end  was  forced  into  the  bore-hole  and  held  in  position 
by  means  of  clamps  and  bolts  which  had  previously  been  cemented  into  holes 
drilled  into  the  surrounding  rock  as  shown  at  B  in  Fig.  235.  This  proved 
effectual  in  sealing  the  bore-hole  itself,  but  when  the  water  was  shut  off,  leakage 
of  water  took  place  through  fissures  in  the  surrounding  country.  Owing  to  the 
gradual  increase  of  water  finding  its  way  into  the  lower  levels,  it  was  found  neces- 
sary to  collect  as  much  water  as  possible  in  the  upper  levels;  and  in  order  to 
assist  in  this,  the  plugging  of  the  bore-hole  was  decided  upon. 

A  double-ram  Cameron  pump  having  cylinders  7-in  diameter,  rams  4-in. 
diameter  and  6-in.  stroke,  was  erected  close  to  the  bore-hole,  and  the  delivery  pipe 
was  connected  up  to  the  i  i/2-in  pipe  at  C.  An  ordinary  cyanide  case  was  used 
for  a  suction  sump,  and  into  this  a  water  pipe  was  led.  Compressed  air  at  a 
pressure  of  80  Ib.  per  square  inch  was  used  to  drive  the  pump.  The  suction 
sump  was  filled  with  water,  the  plug-cock  A  opened,  and  the  pump  started. 
The  sump  was  kept  three-quarters  full  of  water,  and  pine  sawdust  was  gradually 
added  to  the  water,  which  was  kept  well  agitated.  When  about  i  cu.  ft. 
of  sawdust  had  been  pumped  into  the  hole,  it  was  noticed  that  all  leakage  from 
the  face  of  the  rock  had  stopped.  As  the  sawdust  was  intended  only  to  tern- 


330 


HANDBOOK  OF  MINING  DETAILS 


porarily  stop  the  larger  cracks,  the  pump  was  stopped,  the  sawdust  removed 
from  the  sump  and  clean  water  pumped  for  a  few  minutes  into  the  hole.  Port- 
land cement  was  now  added  to  the  sump  in  such  quantities  as  to  form  approxi- 
mately a  mixture  of  25%  cement  and  75%  water,  and  this  was  pumped  into 
the  bore-hole  in  the  same  manner  as  the  sawdust,  cement  being  added  as  re- 


FIG.    235. — DRILL  HOLE  AND   FITTINGS. 

quired.  At  first,  the  pump  worked  quite  freely  against  the  pressure  encount- 
ered; but  as  the  hole  filled  with  cement,  the  pressure  gradually  increased  until  it 
was  necessary  to  assist  the  pump  by  barring  the  fly  wheel  round.  When  one 
cask  of  cement  had  been  used  it  was  found  impossible  to  force  any  more  into 
the  hole.  The  cock  A  was  then  closed  and  after  standing  four  days,  it  was 
opened,  when  it  was  found  that  the  water  had  been  completely  stopped,  and 
there  is  now  no  leakage  whatever  through  the  surrounding  country. 


XII 


VENTILATION  AND  COMPRESSED  AIR 

Approved  Practice  in  Ventilation — Devices  for  Improving 
Ventilation — Theoretical  and  Practical  Consider- 
ations in  the  Use  of  Compressed  Air. 

APPROVED  PRACTICE  IN  VENTILATION 

Ventilation  for  Transvaal  Mines. — Treating  the  subject  of  mine  ventila- 
tion, the  Mining  Regulations  Commission  of  the  Transvaal  makes  recommenda- 
tions for  the  sectional  ventilation  of  the  mines.  The  ventilating  currents  from 
downcast  intakes  should  be  split  at  the  entrance  of  every  working  drift,  such 
entrances  being  provided  with  brattices  so  constructed  that  the  openings  for 
the  passage  of  air  can  be  varied  as  required.  After  passing  through  the  workings 
air  should  be  led  as  directly  as  possible  to  the  main  return  airway. 

Recognizing  the  insufficiency  of  the  ventilation  in  most  of  the  Transvaal 
mines,  it  is  recommended  that  in  all  portions  of  a  mine  or  workings  where  the 
natural  ventilating  current  is  insufficient,  suitable  mechanical  appliances  for 
ventilation  be  erected  and  operated.  The  courses  for  the  supply  of  air  to  all 
working  places,  and  of  foul  return  air  from  such  places,  should  be  kept  separate 
and  disused  drifts,  stopes,  etc.,  where  possible,  should  be  completely  closed  in. 

It  is  further  recommended  that  plans  and  sections  of  every  mine  be  kept  at 
the  mine  office  and  these  drawings  show  airways,  direction  of  air  currents,  posi- 
tion of  brattices,  etc.,  drawings  to  be  posted  to  date  at  intervals  of  not  more 
than  3  months.  Not  less  than  once  every  3  months,  chemical  determination 
of  the  following  samples  should  be  made  at  each  mine:  Air  100  ft.  from  the 
face  of  all  drifts;  50  ft.  from  the  face  of  all  winzes  and  shafts;  from  the  bottom 
of  upcast  shafts;  from  all  stopes  connected  by  only  one  drift. 

With  regard  to  the  subject  of  the  local  ventilation,  the  Mining  Regulations 
Commission  recommended  as  follows:  (i)  That  the  use  of  mechanical  appli- 
ances is  indispensable  for  adequate  ventilation  of  certain  sections  of  a  mine 
outside  of  the  circuit  of  natural  ventilation;  (2)  that  every  working  place  where 
rock  drill  ares  used  be  furnished  with  suitable  arrangements  for  laying  and  re- 
moving dust,  smoke,  gases,  etc.,  and  that  no  man  shall  return  to  a  working  face 
until  the  air  is  free  from  noxious  gases  caused  by  blasting;  (3)  that  the  intake 
pipes  to  compressors  be  led  outside  of  the  engine  room  to  where  the  air  is  of 
suitable  degree  of  purity;  (4)  that  the  lubricating  oil  used  in  compressors  have 
a  flash  point  of  not  less  than  600°  F.;  (5)  that  periodical  inspection  by  a  re- 

331 


332  HANDBOOK -OF  MINING  DETAILS 

sponsible  mine  official  be  required  for  air  cylinders  of  compressors;  (6)  that 
when  mechanical  ventilation  is  not  provided,  all  compressors  be  kept  running 
for  at  least  2  hours  between  shifts  at  not  less  than  20  Ib.  pressure  except  when 
necessary  to  stop  for  repairs;  (7)  that  the  vicinity  of  the  collar  of  downcast 
shafts  be  kept  clear  of  all  cinder  heaps,  and  as  far  as  possible  of  smoke. 

Carbon  Dioxide  Criterion  for  Ventilation.— The  Mining  Regulations  Com- 
mission of  the  Transvaal  has  made  a  number  of  excellent  recommendations 
for  the  bettering  of  underground  conditions.  The  legal  maximum  for  noxious 
carbon-dioxide  is  fixed  at  eight  parts  by  volume  in  10,000  of  air;  in  addition 
four  parts  representing  innocuous  CO2  present  in  the  atmosphere,  three  parts 
where  candles  or  similar  illuminations  are  used,  and  five  parts  in  order  to  meet 
the  difficulties  of  practical  administration  in  regard  to  possible  innocuous  gas 
from  country  rock  and  other  uncertain  sources,  are  allowed.  The  total  limit  is, 
therefore,  20  parts  of  CO2  per  10,000  of  air.  In  the  Lydenburg  district,  where 
there  is  geologically  strong  presumptive  evidence  of  a  production  of  ground  CO2, 
further  investigation  is  recommended  and  an  allowance  of  i  %  maximum 
by  volume  CO2  in  the  mine  air  is  made. 

It  is  stipulated  in  the  recommendations  that  samples  for  testing  purposes  be 
taken  not  less  than  i  hour  after  blasting.  No  allowance  is  to  be  made  for  the 
altitude  of  the  land,  as  affecting  the  allowable  CO  2  limit,  as  many  samples  will  be 
taken  at  'considerable  depth.  The  maximum  permissible  amount  of  carbon 
monoxide,  CO,  in  any  part  of  a  mine  is  not  to  exceed  o.oi  %  and  no 
practically  determinable  amount  of  NO2  shall  be  permitted  in  any  part  of  the 
mine. 

The  commission  seems  to  recognize  that  the  application  of  the  existing 
Transvaal  laws  on  the  subject  of  mine  ventilation  is  open  to  serious  practical 
difficulties.  The  quantity  standard  (70  cu.  ft.  of  air  per  man  per  minute)  is 
judged  as  less  satisfactory  than  one  of  quality.  The  quantity  of  carbon  dioxide 
present  is  accepted  as  bearing  a  roughly  constant  proportion  to  the  amount  of 
impurity  present  and  the  carbon  dioxide  is  considered  the  best  criterion  of  the 
sufficiency  of  ventilation. 

Lack  of  Oxygen  in  Hydraulic  Air.— When  the  air  from  the  hydraulic 
plant  at  Ragged  Chutes,  Cobalt  district,  Ont,  was  first  turned  on  it  was  found 
that  it  was  practically  impossible  to  burn  candles  in  the  mines  where  it  was  used. 
It  was  claimed  that  this  was  due  to  the  absorption  of  oxygen  by  the  asphalt  with 
which  the  inside  of  the  pipes  were  coated,  and  that  this  effect  would  soon  pass 
off.  It  was  soon  found,  however,  that  hydraulic  air  contains  an  appreciably 
less  percentage  of  oxygen  than  ordinary  air,  and  analysis  demonstrated 
that  it  contained  only  17.7%  oxygen,  which  is  3%  lower  than  ordinary  air. 
This  is  due  to  the  oxygen  going  into  solution  in  the  water  during  compression, 
when  a  pressure  of  130  to  135  Ib.  per  square  inch  is  maintained.  The  lack 
of  oxygen  does  not  apparently  trouble  the  miners,  but  besides  the  difficulty 
experienced  in  keeping  lights,  the  effect  of  the  gases  from  exploded  dynamite  is 


VENTILATION  AND  COMPRESSED  AIR 


333 


much  quicker  and  more  serious  than  was  found  to  be  the  case  with  air  com- 
pressed by  machinery. 


DEVICES  FOR  IMPROVING  VENTILATION 

Wrinkles  for  Ventilating  Mine  Workings. — The  schemes  for  aiding  the 
ventilation  of  a  tunnel  or  shaft  in  out-of-the-way  places  are  interesting,  and 
often  effective.  In  a  shaft  the  prospector  often  builds  a  fire  at  one  side  on  the 
bottom.  This  is  especially  efficient  in  a  two-compartment  shaft  that  is  timbered 
close  to  the  bottom.  A  little  sheet-iron  stove  with  a  long  chimney  to  the  surface 
is  an  "improvement"  over  the  open  fire.  Sails  are  sometimes  rigged  to  deflect 
the  wind  down  a  sheet-iron  pipe  to  the  shaft  bottom.  Ventilation  at  tunnel 
faces  is  helped  by  a  simple  sheet-iron  pipe  fitted  with  an  elbow  at  the  portal 


FIG.    236. — JET  FOR  VENTILATING   BY   COMPRESSED  AIR. 

and  having  a  vertical  length  of  pipe  set  in  the  elbow.  A  small  stove  may  be 
inserted  at  the  elbow,  which  draws  air  from  the  drift  and  uses  the  vertical  pipe 
as  a  smoke  stack.  Small  wooden  fans  are  fitted  with  footpower  attachments 
like  that  used  on  grindstones. 

Ventilation  by  Suction  (By  Arthur  O.  Christensen) . — The  following 
method  for  sucking  air  through  a  pipe,  although  not  new,  may  be  novel  to  some 
and  a  suggestion  to  others.  Fig.  236  shows  an  arrangement  of  the  apparatus 
that  has  been  found  satisfactory  in  La  Noria  mine,  Zacatecas,  Mexico.  A  pipe 
about  2  1/2  in.  in  diameter  or  a  wooden  conduit  4  in.  square,  is  laid  in  the 


334  HANDBOOK  OF  MINING  DETAILS 

working  to  be  ventilated  by  suction.  Into  the  lower  end  of  the  pipe  a  3/8-in. 
pipe  is  inserted  and  bent  or  fitted,  as  shown  in  the  illustration.  This  is  coupled 
direct  to  the  compressed  air  line.  When  the  valve  is  opened  the  jet  of  com- 
pressed air,  rushing  into  the  larger  pipe  and  parallel  to  its  direction,  creates  a 
strong  suction  in  the  pipe  or  conduit,  producing  the  ventilating  current. 

In  operation  it  is  better  to  use  the  full  air  pressure  available,  and  cut  down 
the  amount  used  by  the  size  of  the  nozzle  rather  than  employ  a  large  nozzle  and 
only  partly  open  the  valve,  as  is  sometimes  done.  Where  the  larger  pipe  is  not 
over  4  in.  in  diameter,  a  3/8-in.  pipe  tipped  with  a  i/4-in.  nozzle  is  large  enough 
for  a  3o-lb.  air  pressure.  For  higher  pressures  and  where  it  is  necessary  to  be 
economical,  an  aperture  of  from  1/8  to  1/4  in.  may  be  used.  The  nozzle  should 
be  placed  in  the  pipe  or  box  at  a  point  so  situated  that  the  jet  issuing  from  it  will 
be  spread  out  to  fill  the  pipe  before  leaving  it.  The  higher  the  air  pressure  used 
the  farther  back  the  nozzle  need  be  placed.  I  have  found  that  placing  the  nozzle 
12  to  1 8  in.  from  the  outlet  of  the  pipe  was  about  right.  If  the  nozzle  is  put 
farther  back  than  is  necessary  the  pipe  ahead  of  it  hinders  the  rush  of  air,  and 
thus  impairs  the  suction  efficiency. 

In  the  case  of  an  opening  where  it  is  desired  to  blow  air  into  rather  than  draw 
it  out,  about  twice  the  amount  of  air  can  be  carried  in  by  laying  a  second  pipe 
line  and  putting  such  a  jet  on  the  inner  end.  This  arrangement  not  only  secures 
the  benefit  of  the  compressed  air,  but  also  makes  it  suck  in  an  equal  amount  of 
air  through  the  second  pipe  line.  Of  course,  this  is  suitable  only  for  such  dis- 
tances within  which  it  would  pay  to  lay  the  second  pipe  line  in  order  to  save 
compressed  air. 

Ventilating  with  Compressed  Air. — The  practice  of  turning  compressed 
air  into  a  ventilating  pipe  to  induce  an  air  current  is  general  in  the  Cceur  d'Alene 
mines.  This  is  undoubtedly  the  simplest  method  of  ventilating  drifts  when 
compressed  air  is  at  hand  and  power  to  operate  a  fan  blower  is  not  available. 
On  the  i2Oo-ft.  level  of  the  Hecla  mine  at  Burke,  air  is  drawn  in  this  manner  500 
ft.  from  the  face  of  a  drift  to  the  shaft.  Twelve-inch  pipe  is  used  and  a  piece  of 
3/4-in.  pipe  turned  up  at  the  end  serves  as  the  air  nozzle.  The  air  current  is  in 
this  instance  sucked  500  ft.  through  the  fan  pipe,  the  air  jet  being  introduced 
into  the  fan  pipe  about  15  ft.  above  the  bend  at  the  shaft. 

A  different  scheme  is  used  on  the  i6oo-ft.  level  of  the  Mace  mine.  Here  the 
air  jet  is  applied  within  a  few  feet  of  the  suction  end  of  the  fan  pipe.  In  this 
manner  a  current  of  air  is  forced  400  ft.  to  the  shaft  through  8-in.  fan  pipe.  The 
nozzle  is,  however,  different  in  this  case,  being  made  of  i/2-in.  pipe  bent  in 
circular  shape  so  as  to  just  fit  around  the  interior  of  the  fan  pipe.  The  coil  is 
drilled  with  a  number  of  i/8-in.  holes  on  the  side  opposite  the  suction  end  of  the 
fan  pipe.  It  is  claimed  that  this  acts  as  a  more  efficient  nozzle  and  requires 
much  less  air  than  does  turning  in  the  air  in  a  single  jet.  These  nozzles  may 
be  used  at  a  number  of  places  in  the  fan  pipe  if  one  will  not  draw  a  current  of 
air  sufficient  for  proper  ventilation. 


VENTILATION  AND  COMPRESSED  AIR 


335 


Scheme  for  Ventilating  the  Working  Face. — In  order  to  spray  muck  piles 
at  the  face  of  ill- ventilated  drifts  and  assist  the  ventilation  in  a  less  wasteful  man- 
ner than  by  "  blowing  out"  the  drift  with  air  from  the  drill- supply  line  the  appara- 
tus shown  in  Fig.  237  has  been  adopted  at  several  large  mines.  A  pipe  connec- 
tion is  provided  from  a  water-supply  barrel  to  the  air  line  a;  this  air  line  is  en- 
larged at  b.  To  spray  the  muck  pile  the  valve  A  is  closed  and  water  run  into 
b  by  opening  valve  B.  The  air  is  then  turned  on,  after  B  has  first  been  closed 
again.  In  this  way  much  less  air  is  consumed  than  by  the  ordinary  method  of 
blowing  out,  and  the  water  absorbs  the  gases  contained  or  held  by  the  muck. 


FIG   237. — WATER  AND  AIR-LINE  CONNECTIONS   FOR  SPRAY. 

A  Hydraulic  Air  Blast. — A  hydraulic  air  blast  is  easily  rigged  up  where 
water  under  high  head  is  available,  and  serves  satisfactorily  for  affording  ventila- 
tion, supplying  the  blacksmith  shop,  etc.  Three  holes  are  bored  into  a  tight, 
strong  barrel,  one  in  the  top  and  two  on  the  sides,  as  indicated  in  Fig.  238.  Into 
the  one  in  the  head  of  the  barrel  a  funnel  is  inserted  and  fitted  tightly.  Pipes  are 
tapped  into  the  other  holes  and  preferably  some  sort  of  valve  or  spigot  arrange- 
ment provided  on  each.  A  smaller  pipe  connected  with  the  water  supply  opens 
into  the  funnel,  the  end  of  the  pipe  being  set  a  couple  of  inches  above  the  throat 
of  the  funnel.  On  turning  on  the  pressure  water,  air  is  entrapped  and  forced 
into  the  barrel.  The  lower  pipe  serves  for  an  outlet  for  the  water  and  the  upper 
one  as  an  air  discharge.  By  regulating  the  valves  on  the  discharge  pipes  so  that 
the  water  is  let  out  as  rapidly  as  it  enters,  and  setting  the  end  of  the  pressure- 
water  pipe  at  the  proper  height  above  the  throat  of  the  funnel,  a  strong  air  blast 
can  be  maintained.  The  amount  and  pressure  of  the  water  admitted  regulate 
the  amount  of  blast  obtained.  On  the  8oo-ft.  level  in  the  Pittsburgh  mine  near 
Nevada  City,  Calif.,  such  an  arrangement  is  used  with  great  success,  water  being 
taken  from  the  pump  column  to  operate  the  blast. 

Wing  Sail  for  Ventilating  Shafts  (By  A.  O.  Christensen). — After  sinking 
our  shaft  60  ft.  the  gas  from  the  powder  smoke  became  so  bad  that  work  had  to 
be  suspended  until  we  installed  a  "wing  sail."  The  apparatus  consisted  of  a 
canvas  tube,  held  open  by  hoops  made  of  willow  branches,  which  was  run 


336 


HANDBOOK  OF  MINING  DETAILS 


down  the  shaft,  and  to  the  upper  end  of  which  a  wing  sail  was  attached.  Fig. 
239  shows  the  features  of  this  arrangement.  The  sail  is  held  in  place  by  ropes 
stretched  to  nearby  trees.  Auxiliary  ropes  fastened  to  the  middle  of  these  can 


Pressure 
-Water  Intake 


-Air  Discharge 


Water  Discharge 


FIG.    238. — CONVENIENT  AIR  BLAST. 

shift  the  direction  of  their  pull,  thus  altering  the  position  of  the  sail  without 
necessitating  more  than  two  hitching  posts.  The  sail  can  be  turned  to  catch 
wind  from  any  direction.  It  is  necessary  to  set  the  sail  so  that  it  will  draw  air 
out  of  the  shaft.  When  first  tried,  the  air  was  blown  down  but  it  was  found  that 


LGuy 


Guy> 


FIG.    239. — SAIL   FOR   SHAFT   VENTILATING. 

the  heavy  gases  remained  at  the  bottom  while  the  fresh  air  merely  worked  to  the 
surface  again.  When  sucking  air  out,  the  draft  through  the  bag  is  strong  enough 
to  carry  the  heavy  gases  up  without  trouble. 

Ventilating  Stopes  in  Bisbee  (By  F.  W.  Holler)  .—Ventilation  in  the  Bisbee 
mines  is  natural  as  far  as  possible.  Most  of  the  shafts  are  connected  on  the 
different  levels,  and  usually  the  levels  are  cool  enough  for  comfort*and  the  air  is 


VENTILATION  AND  COMPRESSED  AIR 


337 


good.  Levels  are  100  ft.  apart  and  are  connected  in  many  places  by  raises  which 
are  put  up  for  prospecting  purposes  as  well  as  to  help  the  ventilation.  Before 
doing  extensive  stoping,  a  raise  is  put  through  from  one  level  to  the  next.  Then 
stoping  is  started  from  this  raise,  keeping  the  latter  in  the  corner  of  the  stope 
which  will  vary  in  size  from  a  square  section  four  sets  on  a  side  to  one  seven  sets 
on  a  side.  In  some  cases  the  raise  ventilates  the  stope  naturally.  In  other  cases 
the  air  in  the  raise  may  be  good,  but  a  set  or  two  away  it  may  be  just  the  opposite. 
In  this  event  special  methods  of  ventilation  are  necessary,  and  several  of  these 
follow:  The  man  way  set  of  the  raise  is  covered  over  with  plank  on  the  working 
floor  of  the  stope,  and  the  floor  is  removed  in  one  of  the  sets  in  the  far  corner 
of  the  stope,  thus  forcing  the  air  to  travel  across  the  working  floor,  down  into 
the  far  corner  and  back  to  the  raise  on  the  floor  below.  In  this  way  two  floors 
of  a  stope  can  be  ventilated  if  there  is  a  current  of  air  in  the  raise.  When  there 
is  not  a  current  of  fresh,  cool  air  in  the  raise,  small  centrifugal  blowers  run  by 
electric  motors  are  used  to  blow  air  from  a  main  air  passageway  to  the  stope. 


Suction 
from 
Winze 


Open 


-+« 

.A 
B- 

••Closed 

—  »  j  Main  Discharge 

-  ?  <"\ 

*4  Discharge  to, 
*.                  Drift 

V 

cL 
Open 

wer 

Bli 

Suction 
Cloied 

by 

Wooden 
Door 


FIG.    240. — PIPE  ARRANGEMENT  FOR   FAN   BLOWER  USED    ON   COMSTOCK  LODE. 

Six-  or  eight-inch  galvanized  pipe  is  used  to  conduct  the  air.  Occasionally, 
compressed  air  is  used  in  stopes  where  it  is  not  deemed  advisable  to  put  in 
blowers.  Results  obtained  are  not  good  considering  the  power  used  and  the 
quality  of  the  air,  but  by  using  jets  with  the  compressed  air  the  results  obtained 
are  better;  however,  they  do  not  compare  with  those  obtained  by  using  centrifu- 
gal blowers. 

Piping  Arrangement  for  Fan  Blower. — In  Fig.  240  is  shown  a  simple  pip- 
ing arrangement  for  reversing  the  air  current  from  a  fan  blower.     The  scheme  is 


338  HANDBOOK  OF  MINING  DETAILS 

employed  on  the  2ooo-ft.  level  of  the  Union  mine,  at  Virginia  City,  Nev.,  where 
a  Sturtevant,  multivane  blower  is  used  to  supply  air  to  a  winze  from  which  levels 
are  being  opened.  The  main  discharge  of  this  blower  is  20  in.  in  diameter  and 
the  fan  is  run  at  1120  r.p.m.,  being  belt  connected  to  a  2o-h.p.  motor.  The 
power  consumption  is  about  16  h.p.  Ordinarily  the  fan  is  used  merely  to 
blow  fresh  air  down  the  winze  through  the  20-in.  main-discharge  pipe. 
After  blasting  it  is,  however,  necessary  to  draw  the  foul  air  and  gas  from  the 
winze.  The  2o-in.  pipe  then  acts  as  a  suction  pipe,  the  air  current  being  drawn 
(into  the  blower)  through  the  parallel  length  of  1 5-in.  pipe  and  discharged  through 
the  2o-in.  pipe  and  connecting  i5-in.  pipe.  A  wooden  door  or  gate  is  used  to 
close  the  suction  end  of  the  blower  and  the  gates  A ,  B  and  C  in  the  pipes  con- 
trol the  air  current.  The  sketch  shows  the  blower  drawing  air  from  the  winze 
and  discharging  it  into  the  drift.  After  clearing  out  the  winze  the  door  is  removed 
from  the  suction  of  the  fan,  valves  A  and  C  closed,  B  opened,  and  fresh  air  is 
blown  into  the  winze.  This  is  a  much  simpler  arrangement  than  is  usually 
seen  and  requires  a  minimum  amount  of  pipe.  The  wooden  gate  to  close  the 
sue  don  end  of  the  fan  can  be  quickly  constructed  of  a  few  nails  and  some  plank. 
It  is  much  quicker  and  more  economical  to  draw  out  bad  air  than  to  force  it  out 
by  blowing  in  fresh  air.  In  the  winze  mentioned,  no  time  has  to  be  lost  between 
shifts  even  though  the  temperature  of  the  air  would  quickly  rise  to  above  120° 
F.  if  artificial  ventilation  were  not  resorted  to.  By  this  arrangement  it  is  possible 
to  deliver  the  gases  directly  to  an  upcast  air  current  instead  of  allowing  them 
to  mingle  with  the  air  currents  about  the  winze  station. 

Mine  Ventilation  through  a  Drill  Hole. — In  underground  operations  it  is 
necessary  to  have  two  openings  in  order  to  insure  good  ventilation.  The  second 
opening  is  generally  made  by  sinking  a  new  shaft.  In  the  case  cited  here,  the 
ore  could  be  handled  readily  through  one  shaft,  and  .a  churn  drill  hole  was  used 
for  the  second  opening.  The  apparatus  is  a  fan  about  2  ft.  in  diameter  with  a 
horizontal  bottom  discharge  8  in.  in  diameter.  To  this  nozzle  is  fastened  a 
short  piece  of  canvas  air  pipe  slightly  larger  than  the  casing  of  the  drill  hole 
with  which  it  connects.  The  fan  is  belt-driven  by  an  8-h.p.  upright  engine. 
The  engine  obtains  its  steam  from  the  boiler  at  the  shaft  several  hundred  feet 
distant.  The  apparatus  is  in  an  open  field  in  the  southwest  part  of  Joplin,  with 
no  protection  from  the  weather. 

Ventilation  by  Drill  Holes  (By  W.  F.  Boericke).— In  the  shallow  zinc 
mines  of  Wisconsin,  drill  holes,  aside  from  their  primary  purpose  of  serving  to 
prospect  the  ground,  are  of  considerable  use  later  in  ventilating  the  under- 
ground workings.  The  holes  are  usually  put  down  with  churn  drills  and  are 
seldom  much  over  125  ft.  deep,  with  a  diameter  of  6  to  8  in.  The  drilling 
cost  is  usually  about  60  to  80  cents  per  foot,  depending  upon  the  amount  of  drilling. 

Where  the  holes  are  at  different  elevations,  a  small  current  of  air  usually 
passes  down  one  and  up  the  other.  This  can  be  augmented  by  erecting  a  high 
standpipe  above  one,  thus  increasing  the  draft.  If  one  of  the  holes  is  wet,  as 


VENTILATION  AND  COMPRESSED  AIR 


339 


frequently  happens,  the  dripping  water  aids  considerably  in  catching  the  air 
and  carrying  it  down,  on  the  familiar  principle  of  hydraulic  compression.  Some- 
times a  small  fan  and  motor  forces  a  strong  current  down,  or  a  suction  fan  may 
be  used.  Occasionally  a  sail  is  rigged  to  deflect  the  wind  down  the  hole. 

A  more  effective  means  than  the  last  is  employed  at  the  Ross  mine,  Linden, 
Wis.  The  device  is  simple  and  inexpensive,  and  can  be  made  by  the  mine 
blacksmith.  It  consists  of  several  lengths  of  ordinary  y-in.  galvanized  stove  pipe 
joined  together  and  projecting  6  ft.  above  the  ground.  The  bottom  piece  is 


Iron  Weight  to  Counterbalance  « 
Force  ol  Wind    .        __—  -»\ 


FIG.    241. — STOVE-PIPE    VENTILATOR   FOR   DRILL  HOLES. 

sunk  down  the  drill  hole  through  the  soil  until  it  strikes  rock.  Guy  wires  hold 
it  firmly  in  a  vertical  position.  The  top  section  consists  of  two  pieces  of  pipe, 
one  flared  slightly  so  as  to  fit  easily  on  the  other.  Strap  iron,  bent  into  angles, 
is  riveted  as  shown  in  Fig.  241,  and  iron  washers,  with  a  bolt  slipped  through  the 
strap  irons,  allows  one  to  turn  freely  on  the  other.  The  top  piece  has  an  ordi- 
nary stove-pipe  elbow  securely  fitted  to  it,  which  in  turn  is  fastened  to  the  funnel, 
a  wide  concave  piece  dimensioned  as  shown.  The  fan-shaped  piece  on  the  rear 
is,  of  course,  to  turn  the  device  so  as  to  face  the  wind  at  all  times.  A  piece  of 
bar  iron  is  suspended  from  the  front  of  the  mouth  of  the  pipe  in  such  a  way  as 
to  counterbalance  the  force  of  the  wind  when  blowing  against  it. 

Self-acting  Mine  Doors. — A  device,  used  in  a  German  mine,  by  which  a 


340 


HANDBOOK  OF  MINING  DETAILS 


door  across  an  airway  can  be  opened  automatically  by  an  approaching  car  or 
trip  is  illustrated  in  Fig.  242.  The  rail  G  is  supported  horizontally,  at  about 
2  1/2  it.  above  the  ground,  by  two  stulls  on  one  side  of  the  track,  in  such  a  way 
that  the  end  of  the  rail  toward  the  approach  of  a  car  is  closer  to  the  track  than 
the  other  end.  A  slotted  shoe  B  slides  on  this  rail.  Fastened  to  it  is  one  end 
of  a  rope  which  passes  around  suitable  pulleys,  the  other  end  being  fastened  to 
the  outer  edge  of  the  door.  A  counterweight  g  is  also  connected  to  the  sliding 
shoe  to  assist  its  return  movement,  if  the  usual  pressure  is  insufficient.  A 


FIG    242. — SELF-ACTING   MINE   DOORS   FOR   DOUBLE   TRACK   DRIFT   OR  TUNNEL. 

car  coming  in  the  direction  of  the  arrows  strikes  the  shoe  B,  and  by  pushing 
it  ahead  opens  the  door;  by  the  time  the  door  is  open  wide  the  shoe  has  traveled 
sideways  far  enough  to  allow  the  car  body  to  pass  it,  but  the  door  is  prevented 
from  closing  by  the  springs  s,  which  rub  along  the  side  of  the  car.  When  the 
car  has  passed,  the  natural  weight  of  the  door,  which  is  purposely  hung  out  of 
plumb,  assisted  by  the  wind  pressure  and  the  counterweight,  causes  it  to  close. 
A  Mine  Air -door  (By  P.  L.  Woodman). — Details  of  a  mine  air-door  and 
of  an  opening  and  closing  device  used  in  the  motor-haulage  drifts  of  the  Copper 
Queen  mine  are  shown  in  Fig.  243.  The  doors  are  opened  and  closed  without 
stopping  the  train.  When  a  train  approaches,  the  motor  or  end  car  pushes 
the  doors  which  are  free  to  swing  in  either  direction;  upon  opening,  they  are 
caught  and  held  by  the  latches  set  in  both  walls  and  on  each  side  of  the  door  set. 
The  releasing  lever  is  operated  by  a  cord  a  hundred  feet  or  more  in  length  con- 
veniently hung  at  the  roof  of  the  drift.  The  motorman  simply  pulls  the  cord 
in  passing  and  the  levers  release  the  doors  allowing  them  to  swing  shut. 


VENTILATION  AND  COMPRESSED  AIR 


341 


Starting  a  Ventilating  Fan  Automatically  (By  S.  A.  Worcester)  .—The 
Conundrum  gold  mine  at  Cripple  Creek,  Colo.,  now  being  operated  under  a 
lease  to  me,  is  ventilated  by  a  system  of  my  invention,  with  a  large  fan  operated 
by  a  i5-h.p.,  three-phase  induction  motor.  The  motor  is  started  from  i  to  2 
hours  before  the  shift  goes  to  work,  so  that  no  gas  will  remain  in  the  mine  at 
"  tally."  For  the  first  2  or  3  weeks  this  starting  was  done  by  a  miner  who  went 
to  the  mine  early  for  this  purpose.  Later  I  devised  and  put  in  use  the  arrange- 
ment shown  in  Fig.  244,  which  saves  several  dollars  each  month,  besides  being 
accurate  and  reliable. 


FIG.    243. — DETAILS    OF   MINE   AIR-DOOR  AND   CATCHES. 

The  starting  box  A  is  the  ordinary  starting  compensator  used  with  induction 
motors,  and  has  three  "on"  positions  and  the  "off"  position.  The  one-day 
weighted  clock  B  is  wound  by  pulling  down  the  weight  chain  C,  thus  raising 
the  weight  D.  The  marks  on  the  wall  indicate  the  travel  of  the  weight  per 
hour  and  show  how  far  the  weight  should  be  raised  to  start  the  fan  within  a 
given  length  of  time.  When  the  motor  is  stopped,  the  starting  lever  E  is  set 
as  shown,  in  the  "off"  position,  and  is  held  in  this  position  by  the  releasing 
lever  F.  The  releasing  lever  has  a  bucket  G  suspended  near  its  outer  end  and 
with  its  bottom  a  little  below  the  surface  of  the  water  in  the  can  H,  which  is  an 
ordinary  square  5-gal.  oil  can,  with  the  top  cut  out.  The  bucket  is  made 
from  a  piece  of  6-in.  galvanized  air  pipe  with  a  wooden  plug  for  a  bottom;  a 
hole  about  1/8  in.  in  diameter  is  bored  through  the  bottom.  The  bail  K  of  the 
bucket  is  hooked  and  hung  on  the  trigger  L. 

When  the  clock  weight  D  descends  and  lowers  the  long  arm  of  the  trigger, 
the  bucket  is  unhooked  and  drops,  carrying  down  the  releasing  lever  F  far 
enough  to  allow  the  starting  weight  M,  which  is  fast  to  the  handle  E  and  moves 


342 


HANDBOOK  OF  MINING  DETAILS 


with  it,  to  drop  one  notch,  bringing  the  compensator  to  the  first  "on"  position. 
The  bucket  now  sinks  slowly  as  the  water  enters  through  the  small  hole  in  its 
bottom,  requiring  18  seconds  to  lower  the  releasing  lever  so  as  to  pass  the 
second  step  of  the  weight  M,  and  12  seconds  more  to  release  the  third,  or  full- 
speed  step,  30  seconds  being  required  to  bring  the  fan  to  full  speed.  The  water 
has  a  little  oil  on  its  surface  to  prevent  evaporation.  The  operation  of  this 
arrangement  is  independent  of  manual  skill  and  care  and  assures  an  easy  and 
reliable  start,  with  no  danger  of  throwing  the  belt  of!  or  burning  out  fuses. 

The  fan  draws  air  from  the  surface  through  a  long  tunnel.     It  is  situated  in 
a  short  crosscut  from  the  tunnel  to  the  hoist  shaft  and  about  150  ft.  below  the 


FIG.    244. — AUTOMATIC    STARTER   FOR   VENTILATING   FAN. 

underground  electric-hoist  station.  The  air  current  is  forced  directly  down 
the  main  hoisting  shaft.  The  engineer  visits  the  fan  usually  once  each  day,  to 
see  that  the  oil  is  feeding  properly,  and  no  further  attention  is  required,  except 
stopping  and  setting  the  starter  for  the  proper  time. 

Before  this  ventilation  system  was  installed  the  mine,  which  has  about 
3  miles  of  workings,  was  often  entirely  filled  with  mine  gas,  from  the  seventh 
level  to  the  adit-tunnel  entrance,  a  vertical  distance  of  about  800  ft.  The 
seventh  level  was  inaccessible  in  even  the  most  favorable  weather  and  the 
gas  zone  was  more  than  150  ft.  deep  in  all  ordinary  weather.  One  or  more 
men  had  been  killed  in  this  mine  by  the  gas  which  contains,  by  government 
analysis,  10%  of  carbon  dioxide.  The  mine  had  been  practically  aban- 


VENTILATION  AND  COMPRESSED  AIR  343. 

doned  for  5  years  on  account  of  the  gas.  The  ventilation  is  now  perfect  in 
all  parts  of  the  mine,  and  completely  independent  of  weather  conditions.  The 
fungus  or  mold  which  was  at  first  found  throughout  the  mine,  has  all  dried 
up  and  disappeared,  and  the  air  is  cool  and  pleasant;  candles  will  burn  in  all 
parts  of  the  workings. 

(By  J.  H.  Dietz). — A  method  similar  to  that  described  by  Mr.  Worcester 
was  employed  at  the  coal  mine  of  the  Laning-Harris  Coal  &  Grain  Co.,  at 
Wellington,  Mo.  The  fan  at  this  mine  is  of  the  propeller  type,  belt  driven  by 
a  i5-h.p.  direct-current  motor,  and  is  placed  directly  in  the  air  course,  1500  ft. 
from  the  mouth  of  the  slope.  The  motor  is  operated  by  a  type  70  Cutler- 
Hammer  self  starter,  which  replaces  the  elaborate  mechanism  Mr.  Worcester 
has  attached  to  his  ordinary  starting  compensator.  The  simple  solenoid, 
drawing  the  starting  switch  slowly  over  the  contacts  as  soon  as  the  current 
is  turned  on,  takes  the  place  of  the  counter- weight/  oil  can,  6-in.  pipe  and 
system  of  levers,  described  in  the  above  article.  The  fan  can  then  be  stopped 
or  started  from  the  engine  room  simply  by  opening  and  closing  the  switch, 
which  is  equipped  with  a  counter-weight  for  closing,  operated  by  a  string 
attached  to  the  winding  stem  of  an  ordinary  one-dollar  alarm  clock.  This 
enables  the  fan  to  be  started  from  the  engine  room  at  any  predetermined  time, 
and  makes  a  simpler,  cheaper,  more  convenient  and  reliable  arrangement, 
with  the  advantage  that  it  can  be  purchased  properly  made  and  ready  to 
install. 

The  fan  was  manufactured  and  the  starting  arrangement  installed  by  the 
Eagle  Foundry  &  Machine  Co.,  of  Fort  Scott,  Kan.  In  addition  to  the  equip- 
ment described,  the  motor  is  supplied  with  a  variable-speed  controller,  without 
release,  so  that  the  fan  can  be  operated  with  a  50%  variation  in  speed, 
depending  on  the  weather  conditions  and  the  mine  resistance.  This  fan 
requires  no  attention,  except  for  oiling,  and  is  equipped  with  special  self-oiling 
boxes,  so  that  one  trip  a  week  is  sufficient  attention  for  the  entire  equipment. 

When  the  fan  was  installed,  there  was  a  delay  in  shipment  of  the  speed  con- 
troller, and  the  fan  was  connected  direct  and  run  at  the  normal  speed  of  the 
motor.  The  fan  gave  so  much  air  that  it  became  necessary  to  cover  one-half 
of  the  discharge  opening  with  a  temporary  wood  brattice  to  enable  the  miners 
to  hold  a  light  anywhere  in  the  workings.  The  fan  is  now  running  at  minimum 
speed,  with  capacity  for  50%  increase,  to  take  care  of  the  future  growth 
of  the  mine. 

THEORETICAL  AND  PRACTICAL  CONSIDERATIONS  IN  THE  USE  OF 
COMPRESSED  AIR 

Volumetric  Efficiency  of  Air  Compressors  (By  F.  D.  Holdsworth)  .— 
The  term  "piston  displacement"  or  "displacement  capacity,"  commonly  used 
by  air-compressor  builders  as  a  measure  of  capacity,  expresses  the  quantity 


344  HANDBOOK  OF  MINING  DETAILS 

of  air  which  would  be  delivered  by  a  compressor  in  which  there  were  no  losses 
to  prevent  a  discharge  of  a  cylinderful  of  air  at  every  stroke. 

Certain  losses,  however,  are  unavoidable.  These  include:  The  reduction 
of  cylinder  volume,  due  to  the  space  occupied  by  the  piston  rod;  clearance 
space  at  each  end  of  the  cylinder;  leakage  past  the  piston  and  the  inlet  and 
discharge  valves;  failure  to  completely  fill  the  cylinder  during  the  intake  stroke, 
due  to  loss  of  pressure  through  inlet  ports  and  passages;  rarefaction  of  the  in- 
coming air  by  absorption  of  heat  from  the  air  passages  and  piston.  These 
losses  materially  reduce  the  quantity  of  air  actually  delivered;  and  the  ratio 
between  the  actual  delivery  and  the  theoretical  displacement,  expressed  in 
per  cent.,  is  termed  " volumetric  efficiency."  This  is  sometimes  measured 
from  indicator  cards  by  dividing  the  length  of  the  atmospheric  line  included 
within  the  boundary  lines  of  the  card  by  the  total  length  of  the  card.  Results 
obtained  by  this  method  are  misleading,  as  they  invariably  indicate  that  a  com- 
pressor is  being  operated  at  greater  efficiency  than  actually  is  the  case.  Com- 
pressors showing  efficiencies,  as  calculated  from  indicator  cards,  as  high  as 
95%  have  been  found  to  have  efficiencies  of  85%  or  even  less  when  the 
actual  air  delivered  was  carefully  measured.  For  instance,  a  compressor, 
through  faulty  design  of  its  inlet  valves  or  having  insufficient  inlet- valve 
area,  might  have  its  cylinder  filled  with  air  at  2  Ib.  below  atmospheiic 
pressure,  which  would  cause  a  serious  drop  in  volumetric  efficiency,  yet  with 
leaky  discharge  valves  or  with  considerable  absorption  of  heat  through  contact 
with  heated  surfaces,  the  pressure  existing  in  the  cylinder  at  the  completion  of 
the  intake  stroke  might  be  almost  or  quite  up  to  atmospheric  pressure.  An 
indicator  card  taken  under  such  conditions  would  naturally  lead  to  the  con- 
clusion that  the  cylinder  was  practically  full  of  air  and  that  its  volumetric 
efficiency  was  correspondingly  high. 

In  order  to  determine  with  accuracy  the  quantity  of  air  actually  compressed 
and  delivered,  the  quantity  of  air  entering  or  leaving  the  compressor  must  be 
measured.  The  measurement  of  the  entering  air  by  a  gasmeter,  for  instance, 
is  a  troublesome  matter,  owing  to  the  large  volumes  to  be  handled  and  to  the 
fact  that  the  pulsations  of  the  compressor  might  affect  its  accuracy.  The 
calibration  of  such  large  meters  ;s  likewise  difficult. 

Measurement  of  the  air  after  compression  is,  therefore,  usually  attempted. 
In  small  compressors  the  air  is  sometimes  compressed  into  receivers  of  known 
capacity  or  is  measured  by  allowing  it  to  displace  water  in  such  receivers,  the 
quantity  of  free  air  delivered  being  proportional  to  the  amount  of  water  dis- 
placed; but  a  much  more  convenient  method  and  one  which  may  be  applied 
to  compressors  of  large  or  small  capacity,  with  equal  accuracy  and  with  inex- 
pensive apparatus  and  preparation  for  test,  is  by  discharging  the  compressed 
air  through  orifices  of  known  area  and  determining  the  quantity  of  equivalent 
free  air  by  calculation. 

The  apparatus  for  this  method  consists  of  a  manifold,  as  large  or  larger 


VENTILATION  AND  COMPRESSED  AIR  345 

than  the  discharge  pipe  of  the  compressor,  with  numerous  branches  having 
orifices  of  different  diameters  attached  and  equipped  with  valves.  One  that  I 
use  has  eight  orifices,  ranging  from  3/32  to  5/8  in.  in  diameter.  These  orifices 
are  carefully  reamed  holes  in  steel  plates,  which,  for  the  larger  sizes,  are  i  /  2  in. 
thick,  and  for  the  smaller,  3/8  in.  thick.  The  back  or  pressure  side  of  the 
hole  has  its  approach  rounded  to  a  radius  1/16  in.  less  than  the  thickness  of  the 
plate,  leaving  the  remaining  i/i6-in.  length  of  the  hole  cylindrical.  After  the 
hole  is  thus  finished,  its  actual  diameter  is  carefully  determined  by  micrometer 
and  its  area  calculated. 

The  rate  of  flow  through  this  type  of  orifice  is  obtained  by  the  use  of  Flieg- 
ner's  formula,  the  accuracy  of  which  I  have  verified  by  carefully  conducted 
tests  in  forcing  compressed  air  contained  in  receivers  of  known  volume  through 
these  orifices  by  displacing  it  with  water.  It  is  better  to  use  a  number  of  small 
orifices,  as  the  formula  is  known  to  give  unreliable  results  on  orifices  much 
larger  than  5/8  in.  diameter. 

The  manifold  is  tapped  for  a  pressure  gage  and  a  thermometer  well.  An 
accurate  pressure  gage  should  be  used,  as  it  will  be  noted  from  the  formula 
that  the  quantity  of  air  discharged  is  directly  proportional  to  the  pressure  and 
any  inaccuracies  in  determination  of  pressure  will  materially  affect  the  results. 
A  reliable  thermometer  should  be  used  and  for  a  two-stage  compressor  should 
have  a  scale  reading  not  less  than  300°  F.  Pressure  and  temperature  are  the 
only  quantities  required  to  be  observed  for  use  in  the  formula. 

'  In  preparing  for  a  test,  the  main  air  line  should  be  disconnected  near  the 
air  receiver  and  the  orifices  attached  at  that  point.  All  other  outlets  from  the 
receiver  or  from  the  piping  between  the  compressor  and  the  receiver  should  be 
either  blanked  or  protected  by  valves  known  to  be  tight,  in  order  to  insure 
that  all  the  air  furnished  by  the  compressor  will  be  discharged  through  the 
orifices.  A  thermometer  should  be  placed  in  the  path  of  the  air  entering  the 
compressor  as  near  the  cylinder  as  possible.  For  determining  the  speed  of  the 
compressor,  a  revolution  counter  should  be  attached  at  some  convenient  point. 

In  making  a  test,  the  proper  combination  of  orifices  required  to  maintain 
the  desired  pressure  is  determined  by  experiment,  and  it  is  usually  found 
necessary  to  run  the  compressor  for  about  2  hours,  discharging  through 
these  orifices,  before  the  pressure  and  temperature  reach  a  maximum  and 
remain  fairly  constant.  When  this  point  is  reached,  an  observer,  on  signal, 
records  the  counter  reading  and  another  observer  begins  taking  readings, 
at  i -minute  intervals,  of  the  pressure  and  temperature  at  the  orifices.  The 
observer  at  the  counter  should  then  record  the  temperature  at  the  compressor 
intake.  At  the  end  of  10  or  15  minutes,  sufficient  pressure  and  temperature 
readings  will  be  obtained  and  the  observer  at  the  counter  will,  on  signal,  again 
read  the  counter;  the  difference  between  the  last  and  the  first  counter  reading 
will  give  the  total  revolutions  for  the  interval  of  the  test.  Knowing  the  dis- 
placement of  the  compressor  per  revolution,  the  total  displacement  for  the 


346  HANDBOOK  OF  MINING  DETAILS 

test  period  will  be  the  product  of  the  total  revolutions  and  the  displacement 
per  revolution.  The  quantity  of  air  discharged  through  the  orifices,  deter- 
mined by  the  formula,  using  the  observed  data  at  the  orifices,  divided  by  the 
total  displacement,  will  give  the  volumetric  efficiency. 

If  accurate  results  are  desired,  the  barometer  reading  at  the  time  of  the 
test  should  be  known,  which  may  usually  be  obtained  from  the  nearest  Weather 
Bureau  station.  This,  together  with  the  temperature  at  the  compressor  intake, 
should  be  used  in  the  formula  given  below  for  reducing  the  pounds  of  air  per 
second  obtained  from  Fliegner's  formula  to  cubic  feet  of  free  air  per  minute. 

Fliegner's  formula  is: 

AP 


in  which  G=flow  in  pounds  per  second;  A  =  area  of  orifice  in  square  inches; 
P  =  absolute  pressure  of  the  air  behind  the  orifice;  T=  absolute  temperature 
(F.)  of  the  air  behind  the  orifice. 

The  weight  of  a  cubic  foot  of  air  is  found  by  the  formula: 


in  which  W=  weight  of  i  cu.  ft.  of  air;  B  =  barometer  reading  in  inches  of  mer- 
cury; and  T  —  absolute  temperature  (F.)  at  the  compressor  intake. 

The  following  extract,  from  a  test  recently  made  in  New  York  City  on  a 
two-stage,  direct-connected,  motor-driven  compressor  to  determine  its  volu- 
metric efficiency,  will  serve  to  illustrate  the  use  of  the  formula.  The  compressor 
had  a  low-pressure  cylinder  26  in.  diameter,  a  high-pressure  cylinder  15  1/2  in. 
diameter,  each  with  a  stroke  of  18  in.  The  piston  rods  in  each  cylinder  were 
2  1/2  in.  diameter.  The  orifices  used  were  as  follows:  2  5/8,  2  1/2  and  i  5/16 
in.  diameter,  having  a  combined  area  of  1.083  m-  The  observed  data  were  as 
follows:  Revolutions  per  minute,  188;  gage  pressure  at  orifices,  97  lb.;  barom- 
eter, 30.1  in.,  or  14.8  lb.;  temperature  (F.)  at  orifices,  251°;  temperature  (F.) 
at  compressor  intake,  41°.  Then, 


per  second.     Then  the  weight  of  i  cu.  ft.  of  air  at  the  intake  temperature 
was 

= 


460+41 
whence 

2'4°^X6o=  1814.4  cu.  ft. 
0.0796 

of  free  air  per  minute  delivered  by  the  compressor. 

This  quantity,  divided  by  the  actual  displacement  of  the  low-pressure  pis- 


VENTILATION  AND  COMPRESSED  AIR 


347 


ton,  gave  the  volumetric  efficiency  in  per  cent.     This  displacement  in  this  case 
at  the  observed  speed,  with  allowance  for  the  piston  rod,  was  found  to  be  2070 

cu.  ft.  per  minute  whence —    —=0.8765,    or  the    compressor    actually    dis- 
charged 87.65  %  of  its  displacement  capacity. 

Testing  Air  Consumption  of  Drills. — The  apparatus  herein  described 
has  been  satisfactorily  used  in  testing  the  air  consumed  by  rock  drills.  As 
shown  in  Fig.  245,  a  vertical  air  receiver  is  connected  to  the  compressor  line 
by  a  i -in.  pipe,  fitted  with  a  globe  valve,  and  a  i-in.  outlet  pipe  is  led  from 
the  receiver  to  the  drill.  Water  gages  are  placed  one  above  the  other  through- 
out the  entire  height  of  the  receiver,  and  a  pressure  gage  is  supplied.  At  the 
bottom  of  the  receiver  a  3-in.  pipe  with  globe  valve,  furnishes  water,  and  between 
the  receivei  and  intake  valve  a  tee  connection  is  provided  as  a  discharge. 


r      Discharge  Connection 


FIG.    245. — AIR  TANK  AND   CONNECTIONS. 

Before  starting  the  test,  water  is  allowed  to  flow  into  the  receiver  until  it  is 
just  visible  in  the  lower  gage,  and  a  chalk  mark  is  made  opposite  this  level. 
The  receiver  is  then  filled  with  air  at  the  desired  pressure,  the  air  shut  off  and 
the  test  begun.  As  the  drill  takes  air  from  the  receiver,  the  operator  maintains 
a  constant  pressure  by  regulating  the  water  valve.  Simultaneously  with  the 
stopping  of  the  machine  a  chalk  mark  is  made  at  the  water  level  then  shown  by 
the  gage  and  the  water  drained  off  in  preparation  for  the  next  test. 

The  distance  between  chalk  marks,  depth  of  hole  drilled  and  time  of  drilling 
are  noted.  The  cross-section  of  the  tank  being  known,  the  distance  between 
the  chalk  marks  makes  it  possible  to  find  the  volume  of  air  used,  at  the  given 
pressure,  and  from  these  figures  the  amount  of  free  air  can  be  computed. 


348  HANDBOOK  OF  MINING  DETAILS 

It  may  happen,  states  Coal  Age,  that  in  spite  of  the  control  provided  by  the 
water  supply,  the  air  pressure  will  decrease  during  a  test.  In  this  event,  the 
amount  of  free  air  used  may  be  calculated  as  follows: 

Let 

P   =  Initial  pressure, 

P!  =  Final  pressure, 

B   =  Height  above  initial  water  level  to  top  of  receiver, 

A   =  Cross-sectional  area  of  receiver  in  square  feet, 

R   =  Rise  of  water  in  receiver,  in  feet, 

H  =  Atmospheric  pressure. 

Then  each  foot  rise  of  water  in  the  tank,  represents  the  consumption  of 
A  cubic  feet  of  air  and  if  the  pressure  had  remained  constant  at  P,  the  volume 

p_l_  TT 

of  free  air  used  would  have  been  given  by  V—RAX — ^ — 

However,  the  expansion  of  the  air  that  remains  in  the  receiver,  from  pres- 
sure P  to  Pv  represents  the  consumption  of  a  volume  of  free  air  equal  to 

/pi      TT  p       I      TT\ 

Fx= A  (B  —  R)  I  — — ^— —  1  and  the  total  amount  of  free  air  used  is  then 

F+  Vv  It  may  prove  to  be  simpler  to  let  V  represent  the  initial  amount  of 
free  air  in  the  tank  at  pressure  P,  and  Vl  represent  the  final  amount  of  free  air 
at  pressure  Px.  Then 

V=AB^- 


and   V—Vi  will  give  the  amount  of  free  air  consumed  during  the  test. 

Proportions  of  Air -mains  and  Branches. — The  accompanying  table, 
showing  the  number  of  branch  pipes  of  a  given  size  that  can  efficiently  be  sup- 
plied with  air  from  a  main  of  given  size,  is  taken  from  a  bulletin  issued  by  the 
Green  Fuel  Economizer  Co.  and  is  based  upon  the  laws  of  the  flow  of  air 
through  pipes.  The  figures  in  the  vertical  columns  to  the  left  are  the  diameters 
of  the  mains;  the  numbers  at  the  head  of  the  vertical  columns,  the  diameters 
of  the  branch  pipes;  the  other  numbers  in  the  table  show  the  number  of  pipes 
of  the  diameter  designated  at  the  top  of  the  vertical  column,  equal  to  one  pipe 
of  diameter  designated  in  the  column  to  the  extreme  left  on  the  same  horizontal 
line. 

For  example,  it  is  desired  to  find  the  diameter  of  the  main  equivalent  to 
thirty  8-in.  pipes.  Follow  down  the  vertical  column  for  8-in.  pipes  until  the 
nearest  number  to  30  is  found,  then  follow  out  horizontally  to  the  left-hand 
column.  The  number  there  found  will  be  the  diameter  of  the  main  required, 
in  this  example  31  in.  Conversely,  the  number  of  pipes  of  a  given  section 
that  a  given  main  can  supply,  can  be  determined  from  the  table. 


VENTILATION  AND  COMPRESSED  AIR 
EQUALIZATION  TABLE  FOR  PIPES 


349 


Diameter 
of  mains 

Diameter  of  branches 

i 

2 

3 

4 

5 

6 

7 

8 

9 

10 

II 

12 

13 

14 

15 

16 

2 

3 

4 
5 

6 
7 
8 
9 

10 

ii 

12 
13 
14 
15 

16 
17 
18 
19 

20 

21 
22 
23 
24 
25 

26 
27 
28 
29 
30 

31 
32 

33 
34 
35 

36 
37 
38 

5-7 
16 
32 
56 

88 
129 

1  80 
244 
3i7 

402 
5oi 
613 
737 
876 

1026 
1197 
I37S 
1580 
1775 

1985 
2250 
2525 
2800 
3060 

3425 
3738 
4100 
4440 
4898 

5312 
5631 
6i54 
6675 

7075 

7735 
8265 
8715 

2-7 

"5.7 

9-7 

16 
23 
32 

42 
56 

7i 
88 
107 
129 
152 

180 
208 
239 
275 
312 

345 
398 
460 
493 
543 

590 
677 
725 
800 
864 

920 
1070 
1140 
1208 
1280 

1355 
1435 
1625 

2-3 

3-6 

5-7 
8-3 

12 

16 
20 

26 
32 
39 
47 
56 

65 
76 
88 

IOO 

114 

130 
145 
160 
1  80 

202 

219 
243 
265 
289 
315 

344 
374 
401 
433 
470 

497 
537 
575 

1.8 

2.8 

4.1 

1.6 
2.3 

i.S 

7-6 
9-9 

12 

16 
19 
23 

27 

32 

37 
43 
49 
56 

61 
7i 
77 
88 
97 

1  08 

121 

129 
141 
151 

168 
184 
196 

212 
229 

242 
260 
279 

4-3 
5-7 

7-o 

2.8 

3-6 
4-5 

1-9 

2-4 

3-i 

i-3 
1-7 

2.2 

1-3 
1.7 

i-3 

ii 
13 
16 

18 

21 
24 
28 
32 

35 
4i 
47 
So 
55 

62 

68 
74 
79 
88 

96 
103 
109 
119 
127 

138 
146 
157 

1.2 

9-9 

ii 
13 
16 
18 
20 

22 
26 
29 
32 

35 

39 
43 
48 
52 
56 

59 
63 
70 
76 
82 

88 
94 

IOO 

6-7 

4.8 

3-6 

2.8 

2.2 

1.8 

1.4 

I  .2 

1.2 

i-3 
i.S 
i-7 

10 
12 
14 

15 

18 

20 
22 
«4 

27 
29 
32 

35 
38 

40 
42 
45 
Si 
56 

60 
64 
68 

7-7 
8.8 

5-7 
6.5 

4-3 
5-0 

3-4 
3-9 

2.8 
3-2 

2.3 

2.6 

1-9 

2  .  2 

1.6 

1.8 

10 
13 
14 
16 
17 

19 

21 

23 
25 
28 

30 
32 

35 
37 
40 

43 

45 
49 

9-8 
10 

12 
13 

14 
15 
17 
19 
2O 

22 
23 
25 
27 
30 

32 

33 
37 

7-8 
8.9 
10 

ii 

12 
13 
14 

16 

i? 
18 
19 

21 
23 

25 
26 
29 

2.4 
2-9 
3-1 

7-6 

8.0 

5-7 

6.4 

4.6 
5-2 

3-8 
4.2 

3-2 

3-5 

9-6 
10 
ii 

12 

13 
14 
15 

16 
18 

19 
20 

22 

7-5 
8.3 
9-  I 

9-9 

IO 

ii 

12 
13 
14 

16 
16 

18 

6.1 

6.8 
7-5 
8.0 

8.9 
9-3 
IO 

II 

12 

13 
13 
14 

5-i 
5-7 

6.2 

6.7 

7-4 
8.0 
8.5 
9-1 

10 

ii 
ii 

12 

4-3 
4.8 

5-2 

5-7 

6.1 
6-5 
7-i 
7-6 
8.4 

8.9 
9-3 

IO 

3-6 
4.1 
4-4 
4-7 

5-i 
5-7 
6.0 

6.4 
7-  i 

7-6 
7-9 
8.6 

Compressor  Precooler. — Compressor  efficiency  can  be  materially  increased 
in  warm  weather  by  a  simple  and  inexpensive  precooler.  It  should  be  empha- 
sized in  the  beginning  that  water  or  moist  air  should  have  no  chance  to  mix 
with  the  compressor  suction.  Fig.  246  shows  how  the  cooling  nest  of  tubes 
should  be  connected  by  a  wood  or  light  iron  conduit  to  the  suction  valves  of 
the  compressor.  The  nest  of  pipes  can  be  made  up  of  odd  sizes  of  iron,  or  even 


350 


HANDBOOK  OF  MINING  DETAILS 


tin  or  galvanized-iron  speaking  tubes  can  be  used.  If  water  is  worth  saving 
it  can  be  pumped  back  at  slight  expense,  though  the  flow  should  be  regulated 
to  just  the  quantity  required  to  keep  the  pipes  wet.  These  should  be  wrapped 
with  thin  cloth  and  should  be  placed  in  the  open,  preferably  where  prevailing 
winds  or  drafts  will  cause  a  maximum  evaporation. 

As  an  extreme  example  of  the  efficiency  of  this  arrangement,  the  following 
may  be  stated:  The  difference  between  the  temperatures  of  wet  and  dry 
thermometers  at  a  large  plant  in  California  in  summer  has  reached  40°,  the 
difference  between  no  and  70°.  This  difference  in  the  temperature  of  com- 
pressor intake  amounts  to  over  8%.  The  arrangement  shown  in  the 
sketch  precludes  the  saturation  of  the  air  with  water,  as  recently  complained  of 
in  South  Africa,  where  precooling  by  spraying  water  directly  into  the  intake 
was  attempted.  In  fact,  if  the  temperature  of  the  water  supply  is  below  the 


Iron  or  Tin  Pipes  wrapped  with  Cloth 
FIG.    246. — PRECOOLER  FOR  AIR  COMPRESSORS. 

dew  point,  and  an  abundance  is  available,  water  will  actually  be  condensed 
out  of  the  air  as  drawn  to  the  compressor  and  can  be  drawn  off  from  the  bottom 
of  the  cool-air  conduit. 

Washing  Air  for  Compressors. — The  site  of  the  compressor  plant  of  the 
Penn  Iron  Mining  Co.  is  on  a  sandy  bottom-land  at  the  base  of  a  hill  that  fur- 
nishes more  or  less  sand  during  windy  weather.  As  the  result  of  these  condi- 
tions sand  would  get  into  the  compressors  and  cause  trouble.  A  scheme  for 
washing  the  air  was  resorted  to  which  is  shown  in  Fig.  247.  A  concrete  box 
5  1/2  ft.  wide,  5  ft.  high  and  16  ft.  long  was  constructed.  In  the  bottom  of  the 
box  three  i2-in.  cast-iron  pipes  were  laid,  extending  the  full  length  of  the 
box.  The  pipe  is  supported  by  the  end  walls.  The  lower  side  of  the 
pipe  is  perforated  with  the  sufficient  number  of  i/2-in.  holes  to  allow  the  air  to 
enter.  Water  is  placed  in  the  box  so  as  to  cover  the  perforations  in  the  pipe 
i  in.  deep.  This,  however,  is  adjustable  and  can  be  arranged  for  any  depth 
necessary.  The  box  is  covered  with  plank  so  that  all  the  air  must  enter  through 
the  water-covered  holes  in  the  i2-in.  pipe.  The  intake  pipe  from  the  com- 
pressor enters  from  the  top  of  the  box  and  does  not  extend  to  the  water;  there- 


VENTILATION  AND  COMPRESSED  AIR 


351 


fore  it  does  not  take  up  much  suspended  water.  However,  the  air  does  absorb  a 
certain  amount  of  moisture  as  it  passes  through  the  water.  To  reduce  the 
amount  of  moisture  in  the  air,  the  air  is  cooled  as  it  passes  from  the  first  stage  of 
the  compressor  to  the  second  stage  by  passing  through  150  ft.  of  water-cooled 
pipes.  A  small  perforated  water  pipe  is  placed  above  the  air  pipe  to  furnish 
water  for  cooling  the  air.  There  is  a  trap  between  the  two  stages  of  compression 
to  catch  the  condensed  water.  L.  F.  Armstrong,  mechanical  engineer  for  the 
company,  designed  this  apparatus. 


FIG.  247. — CONCRETE  BOX  FOR  WASHING  AIR. 

Air  Compressor  Lubrication. — Explosions  within  the  cylinders  of  an  air 
compressor  are  usually  caused  by  the  ignition  of  inflammable  gas,  the  presence 
of  which  is  due  to  the  use  of  too  much  lubricating  oil  of  low  flash  point.  The 
heat  liberated  from  the  air  during  compression  may  cause  vaporization  of  the 
oil  and  the  vapor  mixing  with  the  compressed  air  forms  an  explosive  mixture 
that  may  be  ignited  at  the  temperature  attained  by  the  air  in  the  cylinder. 
Excessive  use  of  oil  is  open  to  the  further  objection  that  oil  tends  to  cause 
sticking  of  the  valves.  Ordinarily,  air  cylinders  and  pneumatic  tools  require 
less  oil  than  steam  cylinders. 

A  lubricant  that  is  free  from  the  above-mentioned  objections  to  the  use  of 
oil  is  soapy  water,  with  which  a  small  quantity  of  flake  graphite  has  been  mixed. 
The  flakes  of  graphite  remain  suspended  in  the  water  until  admitted  to  the 
interior  of  the  cylinder,  where  they  exhibit  a  tendency  to  attach  themselves  to 
the  metallic  surfaces,  imparting  a  superficial  glaze  that  is  smooth,  acquires  a 
high  polish  and  prevents  actual  contact  of  metal  with  metal.  A  small  quantity 
of  the  mixture  provides  a  safe  and  sufficient  lubricating  layer.  As  the  soapy 
water  may  cause  rusting,  it  is  advisable  to  introduce  a  little  oil  into  the  cylinder 


352 


HANDBOOK  OF  MINING  DETAILS 


when  shutting  down  the  compressor.  The  graphite  is  not  affected  by  any 
degree  of  heat  attainable  in  a  compressor  cylinder;  it  will  not  be  carbonized 
or  baked  into  a  hard  or  gummy  mass  to  interfere  with  the  action  of  the  valves, 
and  under  no  conditions  can  it  be  volatilized. 

Storing  Compressed  Air  in  a  Natural  Rock  Receiver. — At  one  of  the 
mines  in  the  Rossland  district  there  are  two  electrically  driven  compressors 
with  a  combined  capacity  of  7500  cu.  ft.  of  free  air  per  minute.  These  machines 
were  described  by  C.  Sangster  in  Power,  Dec.,  1909.  Air  from  the  compressors 
is  stored  in  a  crosscut  the  capacity  of  which  is  not  less  than  22,000  cu.  ft.  In 
free  air  compressed  to  eight  atmospheres,  it  will  hold  176,000  cu.  ft.,  or  the 
entire  output  of  the  compressors  for  23  minutes.  Allowing  that  one-third  of 
this  air  is  available  at  a  working  pressure,  as  cited,  ten  drills  could  be  operated 
for  50  or  60  minutes  after  the  compressor  was  stopped.  The  advantage  of 
such  a  large  storage  is  noticeable  in  the  engine  room.  It  tends  to  balance  the 
rapid  fluctuations  in  the  load,  the  compressor  and  rope  drive  run  more  steadily 
and  the  unloaders  cut  out  less  often.  The  motors  are  not  subjected  to  the 
strains  of  the  load  being  constantly  thrown  off  and  on.  In  the  mine,  a  hoisting 
engine  or  a  group  of  drills  rnay  be  thrown  on  or  off  without  seriously  affecting 
the  air  pressure.  In  short,  it  stores  and  restores  the  air,  piling  up  a  reserve 
when  a  machine  is  stopped  and  giving  it  back  when  a  sudden  call  is  made. 

Using  a  Pump  for  Compressing  Air. — It  is  occasionally  desirable  to  use  a 
pump  as  an  air  compressor  where  only  low  pressures  are  required,  when  the 


•"Compressed 
Air  Outlet 


FIG.    248. — PIPING  FROM  PUMP  TO  TANKS. 


work  to  be  done  is  of  only  a  temporary  character  and  any  makeshift  will  suffice. 
The  scheme  is  shown  in  Fig.  248.  The  drain  valve  is  closed.  The  pump  is 
then  slowly  started  and  when  primed  the  air  valve  on  the  suction  line  is  opened 
just  enough  to  prevent  the  pump  from  entirely  "losing  its  water."  By  proper 


VENTILATION  AND  COMPRESSED  AIR 


353 


regulation  of  this  air  valve  the  pump  will  take  in  a  large  volume  of  air  with 
each  stroke  and  just  enough  water  to  keep  the  plungers  and  valves  fairly  well 
sealed.  When  a  pressure  of  8  or  10  Ib.  is  reached  the  air  valve  on  the  suction 
line  is  closed,  the  pump  takes  water  and  the  receiver  is  nearly  filled.  This 
forces  the  air  out  of  the  receiver  and  increases  the  pressure  at  the  same  time. 

Should  more  pressure  be  desired  the  air-outlet  valve  is  closed  and  the  re- 
ceiver is  drained  into  the  suction  tank.  The  small  valve  shown  on  top  of  the 
receiver  admits  air  when  the  receiver  is  being  drained.  The  operation  men- 
tioned is  then  repeated.  Incidentally  it  is  not  the  most  economical  way  of 
compressing  air. 

Reheating  Compressed  Air  with  Steam. — The  practice  of  reheating 
compressed  air  by  mixing  it  with  steam  is  employed  generally  in  the  Cceur 
d'Alene  mines  of  the  Federal  Mining  &  Smelting  Co.  Results  obtained  at 
these  mines  seem  to  indicate  that  this  is  the  most  economical  and  efficient 
method  of  getting  the  full  measure  of  energy  from  the  air.  At  the  Mace  mines, 
air  at  QO-lb.  pressure  for  drills,  and  steam  for  the  hoist  were  formerly  conducted 
the  3000  ft.  through  the  entry  tunnel  in  separate  pipe  lines.  The  air  is  now 
compressed  to  100  Ib.,  mixed  with  superheated  steam  at  the  compressor  house 
and  piped  into  the  mine  in  one  line  to  supply  both  hoist  and  machine  drills. 
The  daily  saving  by  this  arrangement  is  figured  at  about  $40,  and  bes'des  an 
increase  of  10  Ib.  in  pressure  is  gained  for  drills.  The  steam  plant  formerly 
required  14  tons  of  coal  per  day,  while  from  six  to  eight  tons  is  all  that  is  burned 
now.  The  boiler  at  this  plant  is  rated  at  80  h.p.  and  the  capacity  of  the  com- 
pressor is  4000  cu.  ft.  of  free  air  per  minute.  No  trouble  has  been  experienced 
from  either  freezing  or  condensation. 

Reheater  for  Air  Hoist. — The  six  levels  below  the  Sweeney  tunnel,  in  the 
Last  Chance  mine  at  Wardner,  Ida.,  are  reached  by  an  inclined  winze  contain- 
ing two  skipways  and  a  manway.  A  compressed-air  hoist  operated  in  balance 
serves  these  lower  levels  with  skips  of  3o-cu.  ft.  capacity.  Trouble  was  experi- 
enced from  the  hoisting  engine  freezing,  so  that  reheating  of  the  air  had  to  be 
resorted  to.  Gasoline  torches  playing  on  a  coil  of  air  pipe  were  tried,  but  with 
poor  success,  until  finally  the  scheme  now  used  was  hit  upon.  A  3-in.  perfor- 
ated air  line  is  run  into  the  drum  of  a  4O-h.p.  fire-tube  boiler,  the  air  passing 
up  through  the  heated  water  and  being  piped  to  the  hoist  from  the  steam 
chamber.  A  check  valve  is  used  on  the  air  line  before  it  enters  the  boiler,  so 
that  as  the  reheated  air  is  drawn  to  the  hoisting  engine,  more  air  is  admitted  to 
the  boiler,  but,  at  the  same  time,  water  is  prevented  from  backing  into  the  air 
pipes.  The  air  pipe  in  the  boiler  is  closed  at  its  end  and  drilled  with  i/4-in. 
holes,  through  which  the  air  escapes.  With  the  reheater,  the  air  pressure  is 
raised  from  5  to  15  Ib.,  depending  upon  the  rate  of  consumption,  and  no  trouble 
is  experienced  from  the  hoist  freezing.  Only  a  small  wood  fire  is  kept  under 
the  boiler,  not  more  than  3/4  cord  of  slab  wood  being  burned  per  24  hours. 

Electric  Reheaters. — At  the  Bully  Hill  copper  mines  in  Shasta  county, 
23 


354 


HANDBOOK  OF  MINING  DETAILS 


Calif.,  a  novel  type  of  reheater  is  used  in  connection  with  pumps  operated  by 
compressed  air.  The  arrangement  is  an  electrical  resistance  coil  inclosed  in  a 
pipe  through  which  the  compressed  air  passes  directly  before  being  utilized. 
The  arrangement  was  worked  out  by  H.  A.  Sutliffe,  electrician  for  the  Bully 
Hill  Copper  Mining  &  Smelting  Co.,  and  has  proved  thoroughly  satisfactory. 
The  reheater  consists  of  two  principal  parts,  i.e.,  an  outer  jacket  and  an  inner 
length  of  pipe  upon  which  is  wound  the  resistance  wire.  The  air  line  is  bushed 
to  the  pipe  jacket  and  through  this  jacket  are  tapped,  as  shown  in  Fig.  249, 
two  i/2-in.  holes  provided  with  insulated  stuffing  boxes  through  which  the 
flexible  lead  wire  is  connected  to  the  resistance  coil. 


Asbestos  Packing 


shing 


n 


4  Pipe 


Flexible  Feed 
Wire 


Galv.  Iron  Wire 
8  turns  per 


Mica  Cloth 
/  0.01"  thick' 


\ 

I!  V 

ft 

V 

\ 

\\ 

\ 

\\\ 

N>          v\          *\ 

V  \  A 

Paper 

ft 

\\. 

\\       «       \\ 

\\ 

\\ 

\\            \v            \\ 

nv  T>- 

\\ 

w          \\         \\ 

*--^"  *  lf*-  JP® 

y//////> 

k     26  long 

Detail  of  2"Pipe 


FIG.    249. — ELECTRIC  .REHEATER   USED   AT    BULLY  HILL,    CALIF. 

In  the  design  shown  the  resistance  coil  is  wound  on  a  section  of  2-in.  pipe, 
26  in.  long,  the  jacket  pipe  being  4  in.  in  diameter.  The  central  pipe  is  first 
wrapped  with  i/8-in.  asbestos  paper,  and  this  in  turn  covered  with  mica  cloth 
o.oi  in.  thick.  Over  this  is  wrapped  a  helix  of  No.  14  galvanized-iron,  tele- 
phone wire  pitched  eight  turns  to  the  inch.  At  points  i  in.  from  either  end,  the 
central  pipe  is  tapped  for  set  screws,  at  four  equally  spaced  points  about  its 
circumference.  These  set  screws  serve  to  keep  the  resistance  coil  from  touch- 
ing the  outer  pipe  jacket.  The  wire  coil  is  so  wound  as  to  not  touch  the  set 
screws. 

A  reheater,  as  described,  is  designed  for  a  no- volt  40-ampere  current  and 
will  use  approximately  6  h.p.,  yet  at  the  Bully  Hill  mine  a  saving  of  at  least 


VENTILATION  AND  COMPRESSED  AIR  355 

$6  per  month  has  been  effected,  it  is  claimed,  by  each  reheater  installed.  The 
reheaters  are  credited  with  raising  the  available  air  pressure  5  Ib.  With  the 
electric  reheater  it  is  well  to  have  the  valve  controlling  the  air  engine,  pump,  etc., 
for  which  the  air  is  being  heated,  connected  with  a  pilot  light,  so  that  when  the 
engine  is  shut  off,  attention  will  be  called  to  that  fact  at  once  and  the  reheater 
will  be  disconnected.  If  this  is  not  done  there  will  be  danger  of  burning  out 
the  reheaters  as  they  soon  become  hot  enough  to  destroy  themselves  if  allowed 
to  run  after  the  air  is  cut  off. 

Placing  Air  Pipes  in  Shafts. — Extensions  of  the  compressed-air  mains 
in  the  Champion  shafts  of  the  Copper  Range  Consolidated  Co.,  in  the  Lake 
Superior  copper  country  are  made  in  20o-ft.  lifts.  The  work  is  commenced 
by  placing  a  tee  in  the  shaft  opposite  the  station  at  the  bottom  of  the  lift ;  then 
carrying  up  the  piping  for  200  ft.  to  connect  with  the  air  main  already  in  posi- 
tion. The  tee  at  the  lower  station  is  securely  fastened  by  an  iron  yoke  to  a 
carrier  timber.  The  pipes  are  then  lowered  and  put  together  until  the  next 
level  above  the  station  is  reached.  There  another  tee  is  put  in  the  line  imme- 
diately above  and  below  which  yokes  are  used  both  to  anchor  the  main  and  to 
prevent  swinging  at  that  point.  When  this  tee  has  been  put  in  place  the  other 
pipes  are  lowered  and,  by  using  a  pipe  of  the  necessary  length,  the  top  of  the 
extension  is  brought  to  within  6  or  8  in.  of  the  bottom  of  the  main  already  in 
place.  A  flange  is  screwed  tightly  home  on  the  upper  end  of  the  top  pipe  and 
yokes  are  attached  to  anchor  the  line  in  position. 

The  connection  with  the  part  of  the  main  already  in  place  is  made  after  i 
p.m.  on  Saturdays  at  which  time  no  drills  are  running  in  the  mine  so  that  the 
air  can  be  shut  off  without  interfering  with  mining  work.  Jacks  are  placed 
under  the  lower  end  of  the  extension  pipe  and  the  yokes  are  loosened  so  that  all 
the  weight  comes  on  the  jacks.  The  blind  flange  on  the  lower  end  of  the  part 
of  the  shaft  main  already  in  place  is  removed.  The  flange  on  the  upper  end 
of  the  extension  is  turned  in  the  direction  of  unscrewing  so  that  the  bolt  holes 
in  upper  and  lower  flanges  are  in  line.  The  little  loosening  usually  necessary 
does  not  cause  leakage.  Then  the  2oo-ft.  length  of  pipe  is  raised  by  the  jacks 
until  the  flanges  come  tight  together.  The  flanges  are  then  bolted  together, 
usually  with  a  gasket  between  to  make  a  tight  joint.  The  yokes,  of  which 
there  are  two  for  each  ico-ft.  length  of  pipe,  are  then  tightened  to  hold  the  main 
in  position.  During  the  operation,  large  wrenches  are  used  to  prevent  turning 
of  the  upper  part  of  the  line  when  the  extension  is  being  raised.  Making  the 
connection  takes  an  hour;  two  men  are  needed  at  the  jacks,  four  at  the  yokes 
and  two,  with  the  boss  timberman  at  the  point  where  the  connection  is  made. 

A  Method  of  Hanging  Air  Pipes  (By  Claude  T.  Rice). — The  Copper 
Range  company  intends  to  connect  its  different  properties  in  Michigan  so  that 
in  case  a  compressor  breaks  down  at  one  mine  air  can  be  delivered  to  it  from 
another.  Already  the  Trimountain  and  the  Baltic  mines  are  connected  in  this 
manner.  The  air  pipe  is  carried  above  ground  so  that  any  leaks  can  be  read- 


356 


HANDBOOK  OF  MINING  DETAILS 


ily  detected.  Supports  of  the  type  shown  in  Fig.  250  are  used.  Timber  legs 
have  been  used,  this  having  been  found  a  good  way  to  employ  old  pipe.  Any 
old  piece  of  2-,  2  1/2-  or  3-in.  pipe  or  old  boiler  tube  8  ft.  or  more  in  length  was 
used  for  the  legs.  This  pipe  was  bent  to  a  radius  of  12  in.  at  the  middle  and 
the  legs  given  a  spread  of  i  in.  in  4  in.  Each  piece  of  pipe  was  flattened  at 
the  top  and  a  i-in.  hole  punched  through  it  to  receive  the  3/4-in.  hanger  bolt 
that  holds  the  air  pipe.  These  pipe  supports  are  footed  in  concrete  pedestals 
about  24  in.  on  an  edge  and  buried  in  the  ground.  The  under  surface  of  the 
top  of  the  pipe  is  set  to  grade  so  that  a  constant  and  standard  length  of  hanger 
can  be  used  in  suspending  the  pipes  from  the  supports. 


Support 


Support 


/Support 


Support 


~  Dotted  Lines 
/indicate  Swing 
from  Expansion. 

Supporter) 


FIG.    250. — OLD-PIPE   SUPPORTS   FOR  AIR  MAINS. 

These  supports  are  placed  along  the  line  at  a  maximum  interval  of  25  ft. 
No  expansion  joints  are  used  in  the  entire  line  which  is  about  11/2  miles  long. 
Instead  the  expansion  that  would  occur  in  the  line  with  a  change  in  tempera- 
ture of  100°  F.  is  figured  for  each  straight  stretch  of  pipe.  This  stretch  of 
pipe  is  anchored  at  the  middle,  and  the  expansion  is  taken  care  of  by  the  side 
swing  of  the  pipes  at  the  turns,  or  changes  in  direction.  In  case  this  is  too 
much  to  be  taken  care  of  in  that  way  with  the  ordinary  course  of  the  pipe  a 
double-angle  turn  or  reverse  bend  is  put  in  long  enough  to  allow  the  expansion 


VENTILATION  AND  COMPRESSED  AIR 


357 


to  be  taken  up  by  the  swing  of  the  pipe  at  this  turn  without  danger  of  loosening 
the  joints.  Often  this  turn  is  anchored  in  the  middle  so  as  to  take  care  of 
the  expansion  of  two  stretches  of  pipe,  but  generally  each  turn  is  made  to  serve 
only  one.  In  case  that  the  stretch  of  pipe  that  must  take  up  the  expansion  is 
short,  the  pipes  are  occasionally  put  in  hot  so  that  the  end  pipe  of  the  expansion 
leg  is  pulled  in  the  beginning  in  the  opposite  direction  to  that  in  which  most  of 
the  expansion  will  occur.  Owing  to  the  pipes  being  suspended  in  swings  at 
the  supports,  little  resistance  is  offered  to  the  movement  of  the  pipes,  and  the 
expansion  can  be  taken  care  of  easily  in  this  manner. 

Stopping  Leaks  in  Air  Receivers. — A  convenient  method  of  stopping  leaks 
around  a  loose  rivet  in  air  receivers  or  steel  water  tanks,  or  even  for  emergency 


Interior 
of 


FIG.    251. — TAPER  BOLT  FOR  STOPPING   LEAKS. 

repair  work  on  boilers,  and  one  which  can  be  made  entirely  from  the  outside, 
is  to  use  a  taper  bolt  with  copper  sleeve,  as  illustrated  in  Fig.  251.  The 
head  of  the  faulty  rivet  is  cut  off,  and  the  rivet  knocked  out  of  the  hole  or  else 
the  rivet  may  be  drilled  out.  A  taper  bolt  A,  large  enough  to  pass  through  the 
hole,  and  threaded  up  to  i  1/2  in.  of  the  large  end,  is  inserted  in  the  rivet  hole  and 
a  piece  of  copper  pipe  B,  of  the  same  internal  diameter  as  the  diameter  of  the 
bolt,  is  lipped  over  the  threaded  portion  of  the  taper  bolt;  it  should  project  1/4 
to  3/8  in.  on  each  side  of  the  plates.  A  washer  C  and  nut  D  are  then  put  on 
and  the  nut  screwed  up  with  a  long-handle  wrench.  The  bolt  can  be  used  for 
withstanding  pressures  up  to  200  Ib.  per  square  inch  with  safety.  The  bolt 
may  be  used  for  repairing  other  small  leaks  such  as  may  occur  in  pump  columns 
by  drilling  out  a  hole  at  the  point  where  the  leakage  occurs.  A  variety  of  uses 
for  such  a  bolt  will  be  suggested  by  the  drawing. 

Pipe  Lines  as  a  Factor  in  Rescue  Work. — The  introduction  of  com- 
pressed-air pipe  lines  into  all  the  workings  of  a  mine  might  be  utilized  to  pro- 
vide fresh  air  and  even  food  to  men  imprisoned  after  explosions  or  through 


358 


HANDBOOK  OF  MINING  DETAILS 


falls.  This  does  not  involve  much  expense,  as  mines  are  usually  equipped  with 
compressed-air  apparatus,  and  the  piping  leading  into  the  mine  is  of  such  a 
nature  as  to  withstand  considerable  damage  from  the  exterior.  Telephone 
wires  inserted  within  the  air  pipe  might  also  serve  a  useful  purpose  in  saving 
life. 

Water  in  the  Air  Line. — One  of  the  difficulties  attending  the  use  of  com- 
pressed air  arises  from  an  accumulation  of  water  in  the  pipe  line.  From  time 
to  time  devices  have  been  suggested  to  draw  this  water,  some  homemade  and 
others  of  the  workshop  variety,  but  perhaps  one  of  the  most  simple  and  in- 
genious forms  has  recently  been  developed  in  England.  It  possesses  numerous 
advantages,  among  which  may  be  mentioned  automatic  action,  small  size  and 
light  weight,  which  facilitates  installation. 

In  Fig.  252  is  shown  the  internal  construction  of  this  water  ejector.  It 
consists  of  a  gun-metal  cylinder  with  three  apertures,  two  being  threaded  for 
pipe,  the  third  being  a  small  hole  at  the  bottom,  normally  closed  by  a  small 


FIG.    252. — EJECTOR   VALVE   FOR  AIR  LINE. 


cone-shaped  valve.  This  valve  forms  part  of  a  gun-metal  spindle  carrying  a 
copper  float  and  provided  with  a  plunger,  upon  the  top  of  which  pressure  is 
exerted  by  the  air  in  the  pipe  line.  This  is  balanced  by  an  upward  pressure 
on  the  under  surface  of  the  plunger  from  the  air  from  the  water  inlet.  Under 
normal  conditions,  the  pressures  on  the  piston  and  float  are  balanced.  If, 
however,  water  enters  the  chamber  from  the  water  inlet,  the  float  is  lifted,  its 
length  of  travel  being  limited  by  a  stop,  and  the  water  outlet  is  uncovered.  The 
pipe-line  pressure  from  the  water  inlet  thereupon  blows  the  water  out  of  the 
chamber,  the  valve  remaining  open  until  ejection  is  complete.  When  air  blows 
out  of  the  water  inlet,  the  greater  pressure  on  the  top  surface  of  the  piston 
forces  the  valve  down  into  its  seat,  and  the  emission  of  air  is  stopped.  It  is, 


VENTILATION  AND  COMPRESSED  AIR 


359 


therefore,  impossible  for  air  to  escape  after  the  accumulated  water  has  been 
discharged. 

In  Fig.  253  the  method  of  connecting  the  valve  to  the  pipe  line  is  shown 
diagrammatically.  Where  grit  or  other  foreign  substances  are  likely  to  get 
into  the  pipe  line  a  strainer  valve  X  is  inserted  at  each  of  the  points  indicated. 

Freezing  of  Compressed-air  Pipe  Lines  (By  Stacy  H.  Hill). — In 
northern  countries  great  inconvenience  is  caused  by  the  freezing  of  com- 
pressed-air pipe  lines.  The  difficulty  has  been  eliminated  to  some  extent  at 
permanent,  well-regulated  properties  by  burying  the  pipe.  Even  in  these  in- 
stallations trouble  is  often  experienced  in  the  smaller  lines  to  blacksmith  shop 
or  exploratory  shafts,  which  may  be  at  some  distance.  A  method  whereby  this 
difficulty  could  be  eliminated  for  all  time  would  be  acceptable  and  has  been  the 
cause  of  much  study,  as  nothing  disorganizes  a  force  of  men  so  much  as  the 
gradual  or  sudden  loss  of  air  supply. 


Ejecting 
Valve 

-Drain 
FIG.    253. — PIPING   FOR  EJECTING  VALVE. 

In  the  latitudes  where  weather  from  zero  to  40°  below  is  occasionally  experi- 
enced, the  pipes  freeze  from  the  circumference,  gradually  diminishing  the  pipe 
area  until  the  passage  is  entirely  stopped.  As  a  preventive  of  this,  the  intro- 
duction of  salt  or  sal-ammoniac  has  been  found  very  effective  up  to  the  moment 
of  entire  blocking  of  the  pipe.  At  a  number  of  properties  a  barrel  of  salt 
is  kept  in  the  engine  room  and  at  regular  periods,  usually  at  the  beginning  and 
middle  of  each  shift,  several  pounds  are  introduced  into  the  pipe  line  just 
beyond  the  air  receiver.  The  pressure  is  then  increased  by  the  air  compressor 
and  the  salt  blown  through  the  pipe,  flushing  out  the  ice.  The  quantity  of  salt 
necessary  is,  of  course,  dependent  upon  the  size  of  the  plant.  There  is  a  record 
of  one  line  transmitting  approximately  1000  cu.  ft.  of  free  air  per  minute  for 
1700  ft.,  where  2  bbl.  of  salt  were  used  in  the  course  of  the  five  winter  months 
and  completely  did  away  with  all  freezing  troubles. 

In  pipe  lines  where  sags  exist,  no  trouble  is  encountered  by  freezing  in  the 
dips,  as  the  salt  collects  as  brine,  preventing  freezing.  For  quick  relief  from 


36o 


HANDBOOK  OF  MINING  DETAILS 


a  partly  frozen  line,  the  pipe  is  sometimes  used  as  a  part  of  an  electrical  circuit 
temporarily  until  the  pipe  is  warmed  sufficiently  to  blow  the  ice  out. 

Electric  Heater  for  Air -line  Drains  (By  G.  C.  Bateman). — When  the 
Cobalt  power  companies  first  started  to  supply  compressed  air  on  a  large  scale 
to  the  mines,  trouble  was  experienced  in  the  winter  by  the  water  from  the  air 
collecting  in  the  low  parts  of  the  pipe  lines  and  freezing.  In  the  pipe  lines  of 
the  British  Canadian  Power  Co.,  this  difficulty  was  overcome  by  the  use  of  an 
electric  heater,  designed  by  James  Ruddick,  the  general  superintendent  for 
that  company.  The  device,  as  shown  in  Fig.  254,  consists  of  a  heater  which  is 
placed  in  a  small  box  built  over  the  drain  cocks  in  the  pipe  line.  These  drain 
cocks  are  placed  wherever  there  is  a  drop  in  the  line,  so  that  the  water  will 
drain  both  ways  to  the  cocks. 


Heater  with  coils  for 
220  volt  circuit 

FIG.    254. — ELECTRIC  HEATER   USED    ON   COBALT  AIR   MAINS. 

The  heater,  which  is  placed  underneath  the  drain  cock,  is  so  designed  that 
it  fits  snugly  into  the  box,  and  a  pipe  leads  from  the  cock  to  the  outside  of  the 
box.  This  pipe  is  cut  off  flush  with  the  box  so  that  there  is  no  danger  of  freez- 
ing on  the  outside.  The  frame  of  the  heater  is  made  of  iX  i/4-in.  iron,  and 
on  this  frame  insulation  knobs  i  in.  in  diameter  and  i  1/2  In.  long  are  mounted 
back  to  back,  as  shown  in  the  accompanying  illustration,  one  bolt  being  sufficient 
for  the  two. 

The  coils  are  made  by  winding  No.  14  galvanized-iron  wire  on  a  y/8-in.  rod, 
each  coil  consisting  of  100  turns.  The  heater  takes  220  volts,  each  coil  being 
equivalent  to  u  volts  and  20  amperes.  The  coils  are  arranged  so  that  there 
is  at  least  an  inch  of  space  between  them.  There  is  a  double-pole  switch  with 
3o-ampere  fuses  in  each  box  and  the  wiring  is  mounted  on  cleats  to  prevent 
fire.  Although  the  heater  takes  only  20  amperes  the  stronger  fuses  are  used 
to  take  care  of  the  current  when  starting,  as  the  coils  take  more  current  when 
cold  than  when  warm.  The  power  required  is  4  kw.  for  each  heater. 


VENTILATION  AND  COMPRESSED  AIR  361 

The  British  Canadian  Power  Co.  controls  about  15  miles  of  pipe  line  be- 
tween 6  and  10  in.  in  diameter,  and  several  miles  of  smaller  sizes.  There  are 
about  25  heaters  in  use,  and  since  their  installation  no  trouble  from  freezing  has 
been  experienced. 

This  device  can  be  used  advantageously  wherever  there  is  trouble  from  the 
freezing  of  surface  lines,  and  as  it  is  a  simple  device  it  can  be  built  at  the  property. 
For  pipes  of  smaller  diameter  than  those  mentioned,  a  heater  of  about  half  of 
the  capacity  of  the  one  described  can  be  used,  in  which  case  it  would  be  necessary 
to  have  current  at  1 10  volts,  or  less,  and  sufficient  coils  can  be  connected  in  series, 
to  suit  the  voltage  available.  To  increase  or  lower  the  voltage  of  the  heater, 
it  is  only  necessary  to  add  or  take  out  coils  as  the  case  may  be.  Should  it  be 
found  that  the  heater  does  not  warm  up  sufficiently,  a  coil  or  so  can  be  cut 
out. 


INDEX 


Abandoned  shafts  and  open  cuts,  12 

Acetylene  lamps,  10 

Adams  mine,  242 

Addy,  G.  E.,  46 

Adits  and  drifts,  driving,  101 

Aerial  tramways,  215 

Air  blast,  hydraulic,  335 

-compressor  lubrication,  351 

compressors,    volumetric,    efficiency   of, 

343 

escape  on  small  pump  columns,  316 

exhaust,  preventing  freezing  of,  59 

for  compressors,  washing,  350 

-hammer  drilling  in  sticky  ground,  46 
drills,  boring  flat  holes  with,  60 

hoist,  reheater  for,  353 

lifts  and  eductors,  319 

-mains  and  branches,  proportions  of,  348 

pipes,  hanging,  355 

receivers,  leaks  in,  357 
Allen,  Robert,  50 
Allouez  mine,  12 
Amalgamated  Copper  Co.,  265 
American  Museum  of  Safety,  276 
Anaconda  gates,  295 
Anchoring  wire  ropes,  220 
Anderson,  A.  E.,  24 
Anderson,  W.  S.,  319 
Angels  Quartz  mines,  149 
Arentz,  S.  S.,  147 
Argonaut  mine,  123,  132,  285 
Arizona-Parral  Mining  Co.,  323 
Armstrong,  L.  F.,  146,  351 
Automatically  discharging  bailers,  248 
Automatic  bucket  dump,  257 
-tripping  device,  253 

cut-off  for  electric  pumps,  315 

skip  for  inclined  shafts,  240 

switch,  302 

trip  for  ore  cars,  271 
Automobile  in  mining,  9 
Austin-Manhattan  Consolidated  Mining  Co., 

"5 
Aymard's  dust  collector,  65 


B 


Back  stoping,  modified  system  of,  122 

Baggaley,  W.  B.,  259 

Bailers,  automatically  discharging,  248 

Balaklala  aerial  tramway,  218 

Ball-bearing  turntable,  305 

Barbour,  P.  E.,  132,  166,  313 

Bateman,  G.  C.,  360 

Baltic  mines,  355 

Battery  method  of  stull  timbering,  134 

Belen  mine,  315 

Benito  Juarez  Mines  Co.,  323 

Birmingham    district,     tipple    construction, 

167 

Bisbee  mines,  336 
Blackberry  mine,  Mo.,  28 
Blackburn,  Ward,  46 
Black  Mountain  Mining  Co.,  166,  240 
Blasting  and  handling  of  explosives,  24 

cap,  25 

gelatin,  35 

in  stopes,  method  of,  125 

in  wet  shafts,  29 

placing  holes  for,  102 

preparations  for,  26 
Boericke,  W.  F.,  247,  289,  338 
Bohn,  J.  V.,  144 
Bolts,  securing  loose  rock  by,  74 
Bonanza  Flat  section,  Utah,  112 

mine,  263 
Bonus  system,  70 

Boring  flat  holes  with  air-hammer  drills,  69 
Boston  &  Ely  mines,  201 
Boston  &  Montana  Co.,  317 
Botsford,  H.  L.,  81,  243,  244,  283 
Boudoire,  Louis,  320 
Breast  stoping,  placing  holes  in,  125 
Bristol  mines,  195 

British  Canadian  Power  Co.,  360-361 
Brockunier,  S.  H.,  194 
Brown  Engine  Co.,  202 
Brown,  H.  Lawrence,  53 
Brown,  H.  S.,  126 
Bryant  safety  crosshead,  280 
Bryant,  Thomas,  280 


363 


364 


INDEX 


Bucket  cars,  Joplin,  225 

drill-steel,  222 

dump,  automatic,  257 

Mineville  ore,  224 

-tripping  device,  automatic,  253 

trolley  for  shaft  sinking,  72 
Buckets  for  winze,  self-dumping,  257 

mine,  222 

sinking,  259 

tramway,  219 

Bulkheaded  ore  chutes,  141 
Bully  Hill  Copper  Mining   &  Smelting  Co., 

354 

Bully  Hill  copper  mines,  353,  354 
Bunker  Hill  &  Sullivan,  234 

mine,  Calif.,  97,  no 
Bunks,  improvements  in,  13 
Burke  mines,  257 
Burra  Burra  mine,  144,  267 
Butte-Alex  Scott  Copper  Co.,  69 
Butte  Coalition  Co.,  317 

rapid  shaft  sinking  in,  69 


Cable  clamp  for  tramway,  216 

drum  for  lowering  timber,  194 

old,  uses  for,  186 

Cables,  flat  wire,  device  for  cleaning,  210 
Cableway  hoist  problem,  solution  of  a,  215 
Cage,  Hiawatha  mine,  243 

landing  chairs  for,  289,  et  seq. 

light  mine,  244 

safety  catch  for,  283 

three-deck  man,  243 
Cages,  safety  gates  for,  293 

testing  safety  devices,  287 
Calumet  &  Hecla  Co.,  30,  137,  159,  186,  205, 
206,  231,  306 

mines,  55,  57,  82,  134,  135,  136,  194,  251, 
286 

ore  cars,  231 

Calumet  system  of  lighting  fuse,  30 
Camp  Bird  mine,  74 
Cananea  arc  type  gate,  152 

mines,  152 

ore  bins,  170 
Candle  tests,  30 
Car,  Copper  Range  man,  235 

mine,  side-dump,  229 
turntable  for,  305 

stopping  devices  on  gravity  inclines,    187 

water,  250 


Car,  wooden  ore,  226 

Carbon  dioxide  criterion  for  ventilation,  332 

Carriers,  special,  247 

Cars,  mine,  cradle  for  dumping,  230 

hoisted   per  hour,  determining  the  num- 
ber of,  182 

Cartridges  for  tamping,  32 
Catenary  hoisting  cable,  192 
Centennial-Eureka  ore,  pocket  and  gate,  140 
Cerro  de  Pasco  mines,  170 
Cerro  Prieto  mine,  240 
Chain  ladders  in  waste  chute,  130 
Chairs,  landing,  289 

on  headframe,  287 

on  the  cage,  291 

skip,  at  Argonaut  mine,  285 
Champion  mine,  62 
Chapin  mine,  61,  293 
Charts,  labor  and  tonnage,  as  aids  in  reducing 

costs,  7 

Checking  men  in  and  out  of  mines,  i 
Cheever  Iron  Ore  Co.,  186,  228,  270 

mine,  263 

"Chinaman,"  modified,  146 
Christensen,  A.  O.,  106,  107,  325,  333,  335 
Chuck  bolts,  shaping,  53 

for  piston  drills,  52 
Chute,  bulkheaded,  141 

device  for  clearing  hung-up,  38 

draining,  325 

gate  at  Mammoth  mine,  Kennett,  Calif., 

149 
steel  arc,  152 

skip  loading,  158 
City  Deep,  Ltd.,  159 
Cleaning  drill  holes,  58 

flat  wire  cables,  210 
Clermont  mine,  121,  167 
Cleveland-Cliffs  Iron  Co.,  242,  302 
Clunes  mines,  138 
Coal  lift,  simple  form  of,  196 
Cceur  d'Alene  district,  234,  334,  353 

mine  car,  234 
Cost  sheets,  standard,  3 
Colby  mine,  277 
Cole,  N.H.,  219 
Coleman,  F.  H.,  316 
Collins,  F.  W.,  177 
Columbus  Consolidated  mine,  313 
Combination  post  and  set  timbering  in  shafts, 
82 

timber  hoist  and  winch,  198 


INDEX 


365 


Comparative  strength   of  several  styles   of 

framed  timber  sets,  no 
Compressed  air.     See  also  Air. 

pipe  lines,  freezing  of,  359 

storing  in  a  natural  rock  receiver,  352 

use  of,  343 

Compressor  precooler,  349 
Compressing  air  by  water  pump,  352 
Comstock  Lode,  no,  114,  117 
Concklin,  B.  M.,  109,  127 
Concrete  chute  bridging  a  level,  194 

in  inclined  shafts,  90 

floors  for  shaft  stations,  97 

powder  house,  42 

reinforced,  in  a  tunnel,  112 

storage  bin,  175 

uses  of,  88 

water  column,  317 
Cone  friction  for  mine  hoists,  199 
Continental  Zinc  Co.,  317 
Conundrum  mine,  341 
Convenience  and  protection  of  employes  and 

equipment,  10 
Copper  King  mine,  146 

Mountain  mine,  166 

Queen  mines,  119,  229,  340 

Range  Consolidated  Co.,   41,   62,  209, 

235,  237,  355 
man  car,  235 
ore  skip,  235 
mine,  53   227  330 
Corner  framing  of  shaft  timbers,  75 
Cornwall  mines,  101 
Counterbalance  for  skips,  242 
Cradle  for  dumping  mine  cars,  230 
Crane  for  changing  skips,  267 
Crimping  fuse  caps,  26 
Cripple  Creek  district,  105 
Crosshead,  Bryant  safety,  280 
Crossheads  and  safety  catches,  277 
Crossover  switch,  calculating,  300 
Crushing  ore  underground,  144 
Cummings,  A.  J.,  228 
Cutting  fuse,  26 

timber  by  small  hammer  drills,  59 
Cyanide  tailings  for  stope  fillings,  127 


Daly  West  mine,  121 

Dam,  strength  of  a,  23 

Dangerous  ground  on  the  Mesabi  Range,  127 


Deep  sinking  with  gasoline  hoists,  201 

De  Lashmutt,  I.,  9 

Del  Mar,  Algernon,  143 

Detonating  high  explosives,  37 

Detonators,  necessity  for  strong,  37 

Deutschland  mine,  192 

Diamond  hitch,  17 

Dietz,  J.  H.,  343 

Disposal  of  waste,  22 

Dixie  Queen  mine,  9 

Doe  Run  mines,  289 

Donnelly,  J.,  121 

Doors,  mine,  339 

Drainage,  mine,  343 

Draining  an  ore  chute,  325 

a  shaft  through  a  drill  hole,  323 

with  well  points,  324 
Drifting  with  stope  drills,  105 
Drift  timbering  for  heavy  ground,  117 

timbers,  joint  for,  119 
Drill  bits,  design  of,  46 

mechanical  sharpeners,  50 

for  soft  ground,  46 

holes,  cleaning,  58 

ejecting  sludge  from,  51 

in  opencut  and  tunnel  work,  103 

post  collar,  53 

with  removable  screw,  53 

-steel  bucket,  222 
bundling  of,  61 

steel  handling  at  Champion  mine,  62 
Drilling  into  misfired  holes,  31 

with  double  screw  columns,  60 
Drills  in  wide  stopes,  scaffolding  for,  124 

removing  stuck,  56 

testing  air  consumption  of,  347 
Driving  adits  and  drifts,  101 

inclined  raises  with  stoping  drills,  106 

in  loose  ground,  114 

vertical  raises  with  stoping  drills,  107 
Drums,  rope  capacity  of,  184 
Du  Bois,  W.  F.,  252 
Ducktown  mines,  144 
Dumping  devices,  253 

skip  for  winze,  240 
Dunn  mine,  86 
Dust  arresters,  64 

prevention  on  the  Rand,  64 

water  blast  for  allaying,  67 
Dwyer  dust  arrester,  66 
Dynamite,  25 

thawing,  42 


366 


INDEX 


Eagle  Foundry  &  Machine  Co.,  343 
Economics  of  management,  i 

of  practice,  60 
Edgerton  mines,  138 
Edholm,  C.  L.,  317 
Eductors,  mine,  323 
Electric  heater  for  air-line  drains,  360 

pumps,  automatic  cut-off  for,  315 

reheaters,  353 

turbine  pumps,  unwatering  a  mine  with, 

313 

signal  device,  213 

signals  for  underground  tramways,  212 
Electricity,  thawing  dynamite  by,  44 
Emergency  chairs  on  headframes,  287 
Employes  and  equipment,  convenience  and 

protection  of,  10 
Englebach  Machinery  Co.,  323 
Enterprise  mine,  325 
Equalization  table  for  pipes,  349 
Erie  mine,  194 
Esperanza  mine,  302 
Expansion  joint  for  pipe  lines,  317 
Explosives,  "don'ts"  in  using,  24 

handling  of,  24 

storage  of,  40 


False  set  for  spiling  ground,  115 

Fast  drifting,  101 

Fay,  A.  H.,  189 

Federal  Mining  and  Smelting  Co.,  95,  234 

257,  258,  278,  353 

Finger-pin  timbering  in  swelling  ground,  117 
Finger  chute,  152 
Fisher,  F.  L.,  295 
Flat  rope  vs.  round  rope,  184 
Fleming,  W.  L.,  112 
Floessell,  W.  H.,  298 
Forell,  J.  H.,  58 
Fort  Wayne  electric  drill,  57 
Foundation  Co.,  89  276 
Fox,  J.  M.,  164,  173 
Framing  for  tunnel  sets,  no 

of  round  timbers,  132 
Franklin  mine,  237 

lo-ton  skip,  237 
Freezing  of  air  exhaust,  preventing,  59 

of  compressed-air  pipe  nlies,  359 


Fremont  Consolidated  mine,  87 
Frog,  mining  track,  299 
Fuller,  J.  T.,  31,  34 
Fuse,  table  for  cutting,  28 

Calumet  system  of  lighting,  30 
Fuses,  25,  26,  27 


Gate  for  controlling  mine  water,  329 

for  lump-ore  bin,  150 

for  ore-bin  chutes,  143 

for  ore  chute,  149 
Gates  for  shafts,  294 
Geronimo  mine,  323 
Gold  Cliff  mine,  199 
Goldfield  Consolidated  fire  equipment,  16 

mines,  12,  14,  118,  121,  147 

stoping  at,  121 
Goodale,  S.  L.,  195 
Gowganda  district,  223 
Grade  in  driving,  maintaining,  101 
Granby  Consolidated  Co.,  159 
Graphic  solution  of  skip  loads   177 
Gravity  planes  at  Cheever  mine,  186 

draining,  327 

tram  switch,  301 
Great  Fingall  mine,  329 
Green  Fuel  Economizer  Co.,  348 
Grether,  W.  S.,  212 
Grizzlies,  underground,  144 
Grouting  in  Quicksand,  94 
Guard  rail  and  fastening,  299 
Guards  at  shaft  stations,  296 
Guiding  a  drop  shaft,  89 
Guides  in  shafts,  supporting,  86 
Guy-rope  tightener,  2 1 
Gwin  mine,  267 


H 


Hammer  drills,  cutting  timber  by  small,  59 
Hancock,  H.  L.,  137 

mine,  54 

Hand  bell  signal  wiring,  214 
Handling  drill  steel  at  Champion  mine,  62 
Hanging  air  pipes,  355 
Harmony  A  mine,  263 

B  mine,  263 

Harness  for  lowering  mule  down  a  shaft,  247 
Harris,  H.  E.,  60 
Hartman,  W.  F.,  97 


INDEX 


367 


Haulage  system,  underground,  189 
Headframe  for  a  prospect  shaft,  164 

for  a  winze  hoist,  165 
Headframes,  chutes,  pockets,  etc.,  149 

emergency  chairs  on,  287 

tipples  and  derricks,  163 

wooden,  details  of,  167 
Head  gears,  overwinding,  allowance  in,  167 
Heavy  ground,  drift  timbering  for,  117 

method  of  mining  in,  112 
Hecla  mine,  59,  334 
Hematite  mine,  198 
Herbst,  Professor,  185 
Hiawatha  mine  cage,  243 
High  explosives,  use  of,  34 
Highland  Boy  mine,  7,  170,  216,  218,  219, 

220,  305 

Hildesia  shaft  at  Dickholzen,  93 
Hill,  S.  H.,  59,  359 
Hitches,  moil  for  cutting  timber,  59 
Hoisting  and  transportation,  177 
Hoisting-bucket  hooks,  273 
Hoisting  cable  run  through  a  drill  hole,  192 

cables,  double,  192 

determining  the  rope  speed  in,  182 

drums,  rope  capacity  of,  184 

ropes,  remarks  on,  185 

snatch  blocks  applied  to,  195 

station,  underground,  190 

thimble  for,  276 

uses  for  old,  186 

with  wire  guides,  193 
Hoisting  cages,  5 
Hoists,  195 

cone  friction  for  mine,  199 

deep  sinking  with  gallsone,  201 

safety  hook  for,  274 

sheave  supports  for,  underground,  205 

steam' and  electric,  interchangeable  arra- 
rangement  for,  199 

steam,  for  shallow  mines,  202 

underground,  166 
Holdsworth,  F.  D.,  343 
Holler,  F.  W.,  336 
Holley,  C.  E-,  277 
Homestake  company,  304 

mine,  304 
Hooks  and  thimbles,  273 

hoisting-bucket,  273 

safety  crane,  274 
Hoster,  M.  T.,  26,  310 
Houses,  portable,  14 


Humes,  James,  115 

Hung-up  chute,  device  for  clearing  a,  38 
Hydraulic  air  blast,  335 
lack  of  oxygen  in,  332 


Idler  for  ho  sting  rope  in  inclines,  209 
rope  guard  for,  206 

Inclined  shafts,  concrete  in,  90 

Injection  of  grouting  behind  shaft  tubbing,  93 

Inspection  department  of  the  Goldfield  Con- 
solidated, 1 6 

Institution  of  Mining  and  Metallurgy,  3 

Interchangeable  arrangement  for  steam  and 
electric  hoist,  199 

International  Smelting    &  Refining  Co.,  220 

Iron  Blossom  mine,  86 

Ives,  L.  E.,  72 

J 

Jack  for  machine  drill  columns,  55 

Jackson,  C.  F.,  157 

James  water  blast,  67 

Johnson,  F.  L.,  19 

Joint  for  drift  timbers,  119 

Joker  m'.ne,  263 

Joplin  bucket  cars,  225 

cars  for  boulders,  227 

district,  124 

scraper  and  loading  stick,  35 


Kennedy,  F.  A.,  88 

Kennedy  mine,  101,  117,  254,  263 

Kenner,  A.  R.,  297 

Keystone  mine,  shaft  timbering  at  the,  79 

Klug,  G.  C.,  329 

Knots  and  ties,  17 


Labor  and  tonnage  charts  as  aids  in  reducing 
costs,  7 

wasting  and  labor  saving,  4 
Lake  Shore  Engine  Works,  244 
Lament,  D.,  307 
Lamps,  acetylene,  10 
Landing  chairs,  285 

chair  for  cages,  289,  el  seq. 
for  skips  in  inclines,  286 
Laning-Harris  Coal  &  Grain  Co.,  343 
La  Noria  mine,  333 


368 


INDEX 


La  Ojuela  mine,  193 

Last  Chance  mine,  353 

Latrine,  sanitary  underground,  14 

Lay,  Douglas,  43 

Le  Fevre,  S.  L.,  151,  190 

Leonard  mine,  42,  266 

shaft  No.  i,  317 

Leschen  &  Sons  Rope  Co.,  143,  184 
Leyner  drill,  64 
Lift,  simple  form  of,  196 
Lighting  fuse,  Calumet  system  of,  30 
Lining  for  ore  chutes,  142 
Loading  holes,  27 
Loose  ground,  driving  in,  114 
Lumber,  scheme  for  transporting,  252 
Lump  ore  bin,  gate  for,  150 
Lunt,  Horace,  105 


M 


Machine  drill  columns,  jack  for,  55 

MacCoy,  F.,  302 

MacGregor,  A.  H.,  211 

Mace  mines,  334,  353 

Magazines,  powder,  40 

May,  Lawrence,  257 

McDonald,  P.  B.,  60,  102,  213 

McFarlane,  G.  C.  85 

McGill,  M.  J.,  210 

McMillen,  D.  A.,  78 

Mammoth  Copper  Mining  Co.,  149 

Management,  economics  of,  i 

Measuring  pocket  for  an  inclined  shaft,  160 

for  skips,  157 
Mendelsohn,  Albert,  53 
Mesabi  district,  22,  37 

mining  dangerous  ground,  127 

steel  shaft  sets,  88 
Miami  Copper  Co.,  265 
Mine  air-door,  340 

buckets,  222 

cages,  243 

drainage,  323 

dust  prevention  on  the  Rand,  64 

eductors,  323 

road,  cheap,  194 

signal-switch,  211 

track,  297 

Mineville  ore  bucket,    24 
Mining  records,  i 

Regulations  Commission,  331,  332 

track  frog,  299 


•Misfired  holes,  drilling  into,  31 
Missouri  zinc  district,  21 
Mitten,  L.  F.,  177 
Modified  "  Chinaman,"  146 

system  of  back  stoping,  122 
Mohawk  mine,  58,  97,  306 
Moil  for  cutting  timber  hitches,  59 
Montana  mines,  28 
Morin  safety  crosshead,  277 
Morning  mine,  95,  234,  258 
Morse,  A.  J.  &  Son,  16 
Mother  Lode,  117,  138,  141,  267 
Mount  Morgan  mine,  39 
Munro  Iron  Mining  Co.,  81 

N 

Nagel,  Oskar,  323 

National  Tube  Co.,  274 

Negaunee  mine,  213 

Nelson,  S.  T.,  202 

Nevada-Douglas  Copper  Co.,  147 

Newberry,  A.  W.,  315 

Newport  mine,  i 

Nipissing  mine,  277 

Norden,  F.  F.,  276 

North  Kearsarge  shaft,  160 

North  Star  mines,  52,  229 

O 

Oiler  for  tramway  buckets,  219 
Oiling  tramway  track  cables,  218 
Oke,  A.  L.,  152,  163,  220,  307 
Oliver  Iron  Mining  Co.,  44,  109,  287 
Ore  bins,  170 

gate  for,  150 
-bin  chutes,  gate  for,  143 
car,  wooden,  226 
cars  and  skips,  226 

automatic  trip  for,  271 
chute  construction,  147 
draining  an,  325 
gate  for,  149 
chutes,  140 

bulkheaded,  141 
lining  for,  142 
safeguarding,  142 
crushing  plant  underground,  144 
houses  and  bins,  6 
pocket,  underground,  161 
pockets,  Red  Jacket,  159 
skip,  Copper  Range,  235 


INDEX 


369 


Original  Consolidated  mine,  154,  265,  280 

self -dumping  skip,  265 
Osceola  Consolidated,  207 

mine,  55 
Overwinding  allowance  in  head  gears,  167 

device  for  prevention  of,  210 
Oxygen,  lack  of,  in  hydraulic  air,  332 


Parrish,  K.  C.,  no 

Partitions  in  shaft,  necessity  for,  75 

Pa^coe,  R.  H.,  257 

Patton,  W.  H.,  79 

Penn  Iron  Mining  Co.,  10,  350 

Petersen,  P.  H.,  304 

Pickands-Mather  mines,  212 

Picking  floor,  movable,  146 

Pillars,  recovering  ore  from,  124 

Pipe  lines  as  a  factor  in  rescue  work,  357 

expansion  joint  for,  317 
Piping  arrangement  for  fan  blower,  337 
Piston  drill,  58 

drills,  chuck  for,  52 
Pittsburgh  mine,  335 
Pittsburg-Silver  Peak  mine,  152 
Poderosa  mine,  291 
Pohle  air  lift,  notes  on,  319 
Portable  houses,  14 

winch,  198 

Port  Henry  Iron  Ore  Co.,  263 
Powder  house,  concrete,  42 
with  concrete  roof,  41 

magazines,  40 

storage  underground,  42 
Power    required    to    haul    cars    on    various 

fitches,  184 

Practice,  economics  of.  60 
Primer,  26 

Priming  with  electric  fuse,  38 
Prospect  shaft,  headframe  for  a,  164 
Pump  cylinder,  repairing,  316 

formula,  307 

station  at  Leonard  mine,  Butte,  317 
Pumping  and  draining,  307 
Pumps,  electric,  314 

for  fire  protection,  315 

sinking,  310 
Pursers'  dust  arrester,  64 


Quicksand,  grouting  in,  94 


Quincy  mine,  54 


Ragged  Chutes  mines,  332 
Rainsford,  R.  S.,  124,  285 
Rand  drill  steel  and  bits,  50 
Ray  Consolidated  mine,  143 
Recovering  ore  from  pillars,  124 
Red  Jacket  ore  pockets,  159 

shaft,  186,  205 

workings,  136 
Reh eater  for  air  hoist,  353 
Reheating  compressed  air  with  steam,  353 
Reinforced  concrete  in  a  tunnel,  112 
Repair  shops,  underground,  12 
Republic  Iron  &  Steel  Co.,  10,  12,  167,  170 

mine,  189,  192,  198 
Rescue  work,  13,  357 
Rice,  C.  T.,  7,  10,  16,  41,  56,  82,  94,  134,  170, 

216,  227,  229,  355 
Richards,  S.,  286 
Richards,  W.  J.,  237 
Rigging  ladders  to  reach  stope  backs,  128 
Road,  mine,  194 
Robinson  Deep  mine,  50,  127 
Rock  drills,  46;  see  also  Drills 
Rogers  shaft  at  Iron  River,  Mich.,  81 
Rope  capacity  of  drums,  184 

guard  for  idler,  206 

idlers  for  inclined  shafts,  206 

speed  in  hoisting,  determining  the,  182 

wire  splicing,  19 

wound    on    a    drum,    determining    the 

amount  of,  183 
Ross  mine,  339 

Round  timbers,  framing  of,  132 
Rubidge,  F.  T.,  i 
Ruddick,  James,  360 
Ruttle,  Joseph,  216,  218 


Safeguarding  ore  chutes,  142 
Safety  appliances,  12,  273 

catch  for  cage,  283 

crane  hooks,  274 

crossheads  for  hoisting  buckets,  277 

device  for  cages  at  the  Chapin  mine,  293 

dump  for  sinking  bucket,  254 

gate  for  cages,  293 

hook  for  hoists,  274 


37° 


INDEX 


Salt  Lake  Copper  Co.,  240 

"Sand  filling"  stopes  in  the  Transvaal,  126 

Sand  Grass  shaft,  164 

Sangster,  C.,  352 

Sanitary  underground  latrine,  14 

Santa  Gertrudis  Co.,  323 

Sargeson  crosshead,  277 

Scaffolding  for  drills  in  wide  stopes,  124 

Scheer,  Charles,  14 

Scranton  mine,  157 

Scraper  for  cleaning  stopes,  251 

Semple,  C.  C.,  60 

Self-acting  mine  doors,  339 

tipple,  268 

Self- dumping  bucket  for  winze,  257 
Severy,  C.  L.,  291 
Shaft  gates,  294 

sinking  at  Stella  mine,  New  York,  71 
at  the  Pioneer  mine,  68 
Butte-Alex  Scott  Copper  Co.,  69 
station    in  inclined  foot  wall  shaft,  94 
stations  and  skip  pockets,  94 

concrete  floors  for,  97 
timbering  at  the  Keystone  mine,  79 
timbers,  corner  framing  of,  75 
extending,  78 

holding  with  wire  cables,  87 
placing,  86 
two-way,  73 
work,  68 

Shafts,  inclined,  rope  idlers  for,  206 
placing  air  pipes  in,  355 
strong  partitions  in,  75 
use  of  steel  and  concrete  in,  88 
Shallow  mines,  steam  hoists  for,  202 
Shaping  chuck  bolts,  53 
Shears,  three-leg,  163 

Sheave  supports  for  underground  hoists,  205 
Sheaves,  arrangement  of,  at  the  Tobin  mine, 

206 

Shelton,  Thomas,  323 
Shenango  Furnace  Co.,  88,  203 
Sherman,  Gerald,  229 
Shoemaker,  G.  M.,  299 
Shops,  underground  repair,  12 
Short,  J.  M.,  323 
Shoveling  in  square-set  stopes,  eliminating, 

123 

Side-dump  mine  car,  229 
Signal  device,  electric,  213 
switch,  Baltic  mine,  211 
wiring,  hand  bell,  214 


Signals  for  underground  tramway,  212 
Sinking  buckets,  method  of  handling,  259 

pump  and  its  troubles,  310 
Skip  and  dump  plate  for  vertical  shaft,  238 

chairs  at  Argonaut  mine,  285 

changing  device  at  Leonard  No.  2  shaft, 
266 

dumps  in  New  York  iron  mines,  261 

Franklin  zo-ton,  237 

improvements,  242 

loader  at  the  Original  Consolidated,  154 

loaders,  154 

loading  chute,  158 

Original  Consolidated  self-dumping,  265 

pocket  and  station  at    Leonard  mine, 
Butte,  98 

pockets,  97 

and  shaft  stations,  94 

timber,  242 
Skips,  cages,  cars  and  buckets,  222 

crane  for  changing,  267 

measuring  pocket  for,  157 
Slicing  system,  stoping  with  the,  121 
Smillie,  Sheldon,  90 
Smith  mine,  Mineville,  N.  Y.,  263 
Snake  Creek  tunnel,  112 
Snatch  blocks  applied  to  hoisting,  195 
Soft  ground,  drill  for,  46 
South  Eureka  mine,  141,  242 
Speaking  tubes  in  mines,  12 
Spike,  new  track,  298 
Spiling  ground,  false  set  for,  115 
Splicing  wire  rope,  19 
Splitting  and  spitting  the  fuse,  27 
Square-set  stopes.   eliminating  shoveling  in, 

123 
Staging,  staple  for  temporary,  109 

for  high  set-ups  in  stopes,  129 
Standard  cost  sheets,  3 

ore  chute,  147 

Staple  for  temporary  staging,  109 
State,  B.  A.,  301 
Steam  hoists.     See  Hoists. 

shovels,  breaking  ground  for,  37 
Steel  and  concrete,  uses  of,  88 

ore  chute  for  use  in  high-grade  stopes, 
140 

in  shafts,  uses  of,  88 

shaft  sets  on  the  Mesabi  Range,  88 
Steinem,  Chester,  253 
Stella  mine,  shaft  sinking  at,  71 
Sticky  ground,  air-hammer  drilling  in,  46 


INDEX 


371 


St.  Lawrence  Pyrites  Co.,  71 

St.  Louis  &  San  Francisco  R.  R.  Co.,  22 

Stobel,  E.  G.,  313 

Stoltz,  G.  C.,  150,  186,  214,  223,  250,  261,  270 

Stone,  C.  J.,  69 

Stope  backs,  rigging  ladders  to  reach,  128 

filling,  cheap,  126 

cyanide  tailings  for,  127 
tram  car  for,  227 

sets,  leaning,  132 
Stopes,  high-grade,  steel  ore  chute  for,  140 

scraper  for  cleaning,  251 

staging  for  high  set-ups  in,  129 

timbering  wide,  137 
Sloping,  121 

at  Gbldfield  Consolidated,  121 

drills,  driving  inclined  raises  with,  106 
vertical  raises  with,  107 

with  the  slicing  system,  121 
Stopping  flow  of  water  from  a  drill  hole,  329 

leaks  in  air  receivers,  357 
Storage  bin,  concrete,  175 

of  explosives,  40 
Storms,  W.  H.,  17,  75,  79,  248 
Stuck  drills,  removing,  56 

wrench  for  removing,  56 
Stulls,  placing  and  cutting,  130 
Stull  timbering,  battery  method  of,  134 
Sulphur  Mining  &  R.  R.  Co.,  226,  268 
Sunnyside  mine,  14 
Sutliffe,  H.  A.,  354 
Swelling  ground,  finger-pin  timbering  in,  117 

timbering,  85 
Switch,  automatic,  302 

calculating  a  crossover,  300 

double-gage  turnout,  302 

gravity  tram,  301 
Switch-throwing  device,  304 


Tailings  for  filling,  22,  127 

Tail-rope  haulage  operated  by  skips,  189 

Tamarack  mine,  137,  306 

Tamping,  27 

cartridges  for,  32 
Tank,  wagon  oil,  253 

Tennessee  Coal,  Iron&  R.  R.  Co.,  162,  167, 
170,  268,  276 

Copper  Co.,  35,  128,  144,  267 
Testing  safety  devices  on  mine  cages,  287 
Tests,  candle,  10 


Thawing  dynamite,  42 

by  electricity,  44 
Thimble  for  hoisting  cable,  276 
Three-deck  man  cage,  243 
Three-leg  shears,  how  to  erect,  163 
Tilden,  R.  E.,  42 
Timber,  cable  drum  for  lowering,  197 

sets,  framed,  comparative  strength  of ,  1 10 
Timbering,  75,  no,  130,  134 

drift,  for  heavy  ground,  117 

in  shafts,  combination  post  and  set,  82 

Keystone  shaft,  79 

placing  sills  beneath  square  sets  already 
in  place,  138 

swelling  ground,  85 

wide  stopes,  137 
Timbers,  drift,  119 

extending  shaft,  78 

placing  shaft,  86 

round,  framing  of,  132 

skip,  242 

Tipple    construction    in    the    Birmingham 
District,  167 

revolving,  270 

self-acting,  268 

tram  car,  270 
Tobin  mine,  86,  206 
Tonopah  Belmont  Orehouse,  173 
Tonopah  Mining  Co.,  12,  164,  173,  174,  300 

ore-houses,  170 
Tooele  smeltery,  220 
Track  and  switches,  297,  299 

spike,  298 
Traders'  mine,  44 
Tram  car  for  stope  filling,  227 

for  the  prospector,  223 

with  automatic  door,  228 

tipple,  270 
Tramway  buckets,  oiler  for,  219 

cable  clamp  for,  216 

mine,  126 
Tramways,  aerial,  215 

underground,  electric  signals  for,  212 
Transportation  and  hoisting,  177 
Transporting  lumber,  scheme  for,  252 
Transvaal  Mines  Dept.,  127 

mines,  40,  125 

Mining  Regulations  Commission,  127 
Tregear,  N.  T.,  166 
Trimountain  mines,  355 
Tunnel  sets,  framing  for,  no 
Turgeon,  F.  M.,  175 


372 


INDEX 


Turnout,  double  gage,  302 
Turntable  for  mine  cars,  305 

U 

Underground  haulage  system,  189 

hoist,  1 66 

hoiscing  station,  170 

ore  pocket,  161 

powder  storage,  42 

repair  shops,  12 

station  in  a  Cceur  d'Alene  mine,  95 
Union  mine,  Virginia  City,  Nev.,  338 
United  States  mine,  121 

tramway,  215 

Unloaders  and  dumping  devices,  253 
Unwatering    a    mine    with    electric    turbine 
pumps,  313 

flooded  mines,  307 

shaft  by  compressed  air,  320 
Utah  Consolidated  Co.,  305 
Utica  company,  199 

mine,  130,  149 

V 

Van  Roi  mine,  43 

Ventilating  fan,  starting  automatically,  341 

mine  workings,  333 

stopes  in  Bisbee,  336 

the  working  face,  335 

with  compressed  air,  334 
Ventilation  and  compressed  air,  331 

approved  practice  in,  331 

by  drill  holes,  338 

by  suction,  333 

carbon  dioxide  criterion  for,  332 

devices  for  improving,  333 

of  Transvaal  mines,  331 
Vermont  Copper  Co.,  44,  223 
Vertical  unbalanced  loads  lifted  by  first 

motion  hoists,  177 

Volumetric  efficiency  of  air  compressors,  343 
Vulcan  Iron  Works,  177 


W 


Waldman  mine,  277 
Wallace,  R.  B.,  293 
Wallaroo  &  Moonta  Mining  and  Smelting 

Co.,  137 
mines,  138 

Ward-Leonard  system  of  wiring,  205 
Warren,  W.  H.,  298 
Waste  chute,  chain  ladders  in,  130 

disposal  of,  22 
Water  blast  for  allaying  dust,  67 

car,  two-ton,  250 

in  mines,  utilizing,  317 

in  the  air  line,  358 
Watson,  H.  C.,  193 
Webb  mine,  203 
Wet  ground,  blasting  in,  29 
Wet  shafts,  blasting  in,  29 
Western  Australian  Royal  Commission,  127 
Weston,  E.  M.,  29,  50,  51,  57,  64,  159 
W.  F.  2  shaft,  89 

Whitford-Mills  skip  loading  device,  159 
Wilcox,  L.  L.,  12,  238 
Wilson,  J.  B.,  38 
Wilson,  J.  E.,  122 
Winding    drums,    determining    the  face  of, 

183 

Wing  sail  for  ventilating  shafts,  335 
Winze,  dumping  skip  for,  240 

hoist,  headframe  for  a,  165 

self-dumping  bucket  for,  257 
Wire  cables,  holding  shaft  timbers  with,  87 

guides,  rapid  hoisting  with,  193 

ropes,  anchoring,  220 

splicing,  19 
Witherbee,  Sherman  &  Co.,   142,   146  151, 

175,  189,  190,  243,  263,  270,  315 
Wittich,  L.  L.,  22,  323 
Wolverine  mine,  97,  306 

No.  4  shaft,  95 
Woodman,  P.  L.,  340 
Worcester,  S.  A.,  4,  190,  341 
Wrench  for  removing  stuck  drills,  ^6 


Wagon  oil  tank,  253 


Young,  G.  J.,  114 


RETURN         CIRCULATION  DEPARTMENT 

TO  -^                     1  98  Main  Stacks 

LOAN  PERIOD  1 
HOME  USE 

2 

3 

4 

5 

6 

ALL  BOOKS  MAY  BE  RECALLED  AFTER  7  DAYS. 

Renewls  and  Recharges  may  be  made  4  days  prior  to  the  due  date. 

Books  may  be  Renewed  by  calling  642-3405. 

DUE  AS  STAMPED  BELOW 


MAV 


FORM  NO.  DD6 


UNIVERSITY  OF  CALIFORNIA,  BERKELEY 
BERKELEY  CA  94720-6000 


C.  BERKELEY  LIBRARIES 


C  0  2  T  7  b  b  E  ?  1 


M127C 


TN/4S" 


THE  UNIVERSITY  OF  CALIFORNIA  LIBRARY 


